• <tr id="yyy80"></tr>
  • <sup id="yyy80"></sup>
  • <tfoot id="yyy80"><noscript id="yyy80"></noscript></tfoot>
  • 99热精品在线国产_美女午夜性视频免费_国产精品国产高清国产av_av欧美777_自拍偷自拍亚洲精品老妇_亚洲熟女精品中文字幕_www日本黄色视频网_国产精品野战在线观看 ?

    Research on the Effect of R&D lnvestment lntensity and Sales Expense on the Performance of Biomedical Enterprises

    2023-12-23 09:16:18WangLifeiJiaZhengWuDongmingXinghua
    亞洲社會(huì)藥學(xué)雜志 2023年4期

    Wang Lifei,Jia Zheng,Wu Dongming,Xinghua*

    (1.School of Business Administration,Shenyang Pharmaceutical University,Shenyang 110016,China;2.School of Business Administration,Tangshan Vocational and Technical College,Tangshan 063300,China)

    Abstract Objective To explore the influence of new drug R&D investment and sales expense on the performance of biomedical enterprises.Methods The financial statements of 76 listed biomedical enterprises for 5 consecutive years were selected,and the data were modeled to study the effect of R&D investment and sales expense on the performance of biomedical enterprises by using financial indicators as tools and statistical methods of multiple linear regression.Results and Conclusion Under the premise that the weak related factors such as enterprise scale,life cycle and asset-liability ratio are set as unrelated variables,the R&D investment intensity of biomedical enterprises is negatively correlated with the current performance,which also shows that the R&D of biomedical enterprises has the characteristics of high risk.Besides,the influence of early R&D investment is delayed.However,the sales expense of leading biomedical enterprises with large scales have higher proportion.Meanwhile the greater sales expense of the same enterprise in different periods,the better the enterprise performance is.Biomedical enterprises should consider their own development stage to develop more patented drugs.Besides,they must formulate plans for allocating reasonable sales personnel and cost expense to ensure that enterprises can obtain better benefits.

    Keywords: biomedical enterprise;enterprise performance;R&D expenditure;sales expense

    1 Introduction

    According to the latest National Bureau of Statistics,in the past decade,the total R&D expenditure in China increased from 86.87 billion yuan in 2011 to 278.64 billion yuan in 2021.The increase of R&D investment reflects China’s emphasis on scientific and technological innovation,which is the foundation of economic development.The biomedical industry is highly dependent on continuous innovation and development.In recent years,the National Development and Reform Commission,the State Council and other departments have clearly pointed out that the biomedical industry should be taken as a national key innovation industry.With the introduction of support policies,more and more biomedical enterprises have intensified the investment in the scientific research under the guidance of the government,which injects new vitality into the development of enterprises.

    New drug R&D is a risky business.Despite the great risks,many large biomedical enterprises are involved in new drug R&D because it is essential for their survival.Besides,patients also need new drugs to treat diseases.Therefore,the development and successful registration and marketing of new drugs has become urgent for the survival of the pharmaceutical industry today.With the implementation of product patents in China,the status of the pharmaceutical industry in China has changed significantly in recent years,and more and more enterprises have increased their R&D investment.The source of R&D funds and the maintenance of the capital chain become the focus of enterprises.Therefore,the disposable funds owned by biomedical enterprises will promote or limit the sustainable development of enterprises.

    The goal of each biomedical enterprise is to maximize return on investment (ROI),which means to increase enterprise sales and earn considerable profits for the maintenance and sustainable development of enterprises.Meanwhile,the goal of drug marketing is to meet the needs of customers and obtain profits,which is highly consistent in purpose.Therefore,as the direct driving factor for enterprises to obtain profits,the attention of enterprises is very critical.Since drug sales are different from the sales of other business types,the marketing personnel of pharmaceutical enterprises must understand the real needs,wishes,and attitudes of customers towards products and services.Enterprises need to spend more on training on-site personnel,which enables the sales department to sell products to different customers.Therefore,pharmaceutical enterprises need to pay attention to the marketing and make more investment in understanding the needs and expectations of customers.

    At present,no matter from the perspective of the total volume or proportion of R&D investment amount,the investment intensity of China’s biomedical industry is lower than that of biomedical enterprises in developed countries.What is worse,some China’s biomedical enterprises abandon the R&D and focus on the production of generic drugs to obtain the greatest benefit in a short time.However,some experts in the industry pointed out that the enterprises lacking innovation would have insufficient motivation in the later stage of sustainable development,which hindered the further development of enterprises.Only gaining something in the R&D innovation and correctly playing the role of sales can they promote the growth of enterprise performance.In this paper,76 biomedical enterprises listed on Shenzhen Stock Exchange and Shanghai Stock Exchange from 2015 to 2019 are taken as the samples to study the relationship between the R&D investment-revenue ratio,sales expenserevenue ratio and the net interest rate of shareholders by using multiple linear regression analysis.By controlling the relevant variables,the correlation between the performance of enterprises,investment and sales expense is studied,and a conclusion is drawn.Then,some suggestions are put forward for the capital investment in the production and operation activities of enterprises.

    2 Literature review

    2.1 Literature review of the impact of R&D investment on enterprise performance

    There are many literatures on the impact of R&D investment and new drug innovation in the biomedical industry on enterprise performance,and the scope of research is also wide.Scholars have focused on the influencing factors of R&D and the relationship between R&D investment and enterprise value.For example,whether the biomedical industry should increase the intensity of R&D investment,enterprises need to consider a variety of conditions,external factors such as macro-environment,policy support,government subsidies and tax incentives,and internal factors including capital structure and asset-liability ratio.For different biomedical enterprises,both future sustainable development and the stability of the current capital chain are important,so the selection of R&D investment strategy is affected by many factors.

    Due to the particularity of the biomedical industry,most scholars believe that pharmaceutical enterprises have high R&D investment,low capitalization,low success rate of new drugs and long return on investment cycle,which results in the confusion of scholars on the impact of R&D investment on enterprise performance indicators.Cao Xiaomei (2016)[1]selected 59 representative pharmaceutical listed enterprises in A-shares of Shanghai and Shenzhen exchanges to make a regression analysis on the R&D investment and financial index establishment model of enterprises.She used the least squares method to make an empirical study on the investment and financial index.She found that the R&D investment funds of biomedical enterprises could improve the current performance of enterprises.Besides,the coefficient analysis of regression function showed that although the R&D expenditure had no significant effect on Tobin Q,the lag period in the split time had a significant effect on the performance of enterprises,showing a positive correlation between the two,and there would be a significant weakening effect in the subsequent stage.Zhong Yangmei,et al.(2018)[2]believed that intangible assets in biomedical enterprises accounted for a high proportion.Therefore,they studied the effect of R&D expenditure on the profit of pharmaceutical enterprises.Then,they concluded that there was a significant positive correlation between R&D expenditure and net profit of enterprises.Yu Yan (2014)[3]selected enterprise on GEM to make an empirical study.He concluded that there was a significant negative relationship between R&D expenditure and financial performance.Hao Cailian(2020)[4]made an empirical study which showed that the R&D investment of biomedical enterprises could positively promote the sustainable development of enterprises.Besides,the increase of the investment in R&D funds was helpful for the long-term development of enterprises.However,the number and proportion of R&D personnel of enterprises had no effect on the growth of enterprises,indicating that enterprises should reasonably arrange the number of R&D personnel and strictly assess high-level R&D personnel.Excessive R&D personnel cannot create better performance of enterprises,but it will cause more management costs that further reduce the profit of enterprises.

    2.2 Literature review of the effect of sales expenses on enterprise performance

    The sales expense will directly affect the current enterprise performance.But some research results show that different scholars have not formed a consistent conclusion.Feng Rentao,et al.(2013)[5]studied the effect of sales expenses of pharmaceutical enterprises on the value of enterprises and current business performance,then they concluded that there was a positive correlation between the two.Bao Miaomiao (2014)[6]applied the statistical quantitative analysis method to empirically study the effect of advertising expenses of pharmaceutical enterprises on profit and obtained the positive correlation between the two.However,there would be an inverted U-shaped trend,which meant there was an inflection point in the impact coefficient,and the effect of sales expenses on profit before this point showed an increasing trend.When it was greater than the sales expense at this point,the effect of sales expenses on profit would decrease,so the reasonable sales expense would have an optimal solution to maximize the benefits.Huang Xiaobo,et al.(2018)[7]concluded that the sales expense rate in this year had a significant negative correlation with the financial performance of the enterprise in that year after making an empirical study,and the previous sales expense rate had no effect on the performance of the enterprise in this year.Yan Bin (2020)[8]concluded that there was a significant negative correlation between the sales expense rate and the financial performance of enterprises using an empirical study.Then,he demonstrated that with the premise of unchanged control variables,the corresponding return on equity would decrease by 0.27% after 1% increase in the sales expense rate.

    2.3 Comment of the literatures

    Based on the above literature analysis,it can be seen that there is no consistent conclusion on the relationship between enterprise performance and R&D investment and sales expense.Besides,the conclusions drawn will be different according to various samples selected by the authors.From the multi-faceted analysis,scholars believe that when R&D investment is intensified,enterprise performance will be better.However,sales expense will make enterprise performance worse.Yet,some scholars hold the opposite point of view.In addition,some scholars believe that R&D investment,sales expense and enterprise performance have a significant correlation,and they are the most obvious factors impact on enterprise performance.In this paper,we use the financial data of biomedical enterprises as a sample,apply linear regression model to construct the equation between the two and enterprise performance and analyze the relationship between them.

    3 Empirical studies

    3.1 Study hypotheses

    At present,different scholars have different views on the impact of R&D expenditure and sales expenses on enterprise performance,and the following research assumptions are made based on the query and collation of data.

    3.1.1 Effect of R&D expenditure on enterprise performance

    The operation of biomedical enterprises mainly relies on the sales of drugs.The patented technology and drugs mastered by enterprises are the core competitiveness.Innovation is the fundamental source for the development of enterprises,and R&D is the direct path to produce innovation results.However,the R&D investment of enterprises should balance risks and benefits.Blind investment can lead to the loss of enterprise funds due to R&D failure.The data in the sample shows that the pharmaceutical enterprises in the leading position often have a large proportion of intangible assets,which means that they have more patent rights,occupying the demand market and achieving more profits.At the same time,although some enterprises have a large R&D investment,they do not obtain a higher profits.By calculating the capitalization proportion of R&D investment,we can find that the conversion rate of R&D investment is low because most capital investment are processed,which does not become the assets of enterprises.At present,most scholars believe that R&D investment has a positive impact on the profits of enterprises,but there is a certain lag period in the impact,which can be reflected in the financial indicators beyond the late stage of R&D.

    Based on the above research results,this paper puts forward the hypothesis that there is a significant negative correlation between the R&D investment ratio and the net interest rate of shareholders in the current period.

    3.1.2 Effect of sales expenses on enterprise performance

    The best way for pharmaceutical enterprises to maximize return on investment is earn considerable profits by increasing sales to achieve sustainable development.The goal of drug marketing is to obtain profits by meeting the needs of customers,so the expense of enterprises in the sales will be directly related to the benefits in that year.At present,pharmaceutical enterprises pay more attention to marketing,which also provides impetus to promote enterprise performance.However,while management makes high sales expense strategy,there will also be waste phenomenon.With the reform of the twoinvoice system of the government and the introduction of the “4+7” drug centralized procurement system in recent years,the waste of expenditure in the sales is well limited,enterprises pay more attention to the rationality of sales expense,spending more funds for the development,management and maintenance of the market,strictly controlling the funds in the advertising and business publicity,which in turn achieve better profits.

    Based on the above research,this paper puts forward the hypothesis that there is a significant positive correlation between the sales expense ratio and the net interest rate of shareholders in the current period.

    Both R&D investment and sales expense of enterprises are continuous and dynamic,which will be restricted by time lag.In this paper,linear model does not consider the time factor,and the life cycle stage and size of enterprises are taken as unrelated variables and random error variables.

    3.2 Selection of data and samples

    In this paper,the listed enterprises in the biomedical industry are selected,and the financial statements are derived from the data released by Sina Financial Network.A total of 76 enterprises with large scale in the industry are selected as the sample data from 2015 to 2019,of which the individuals with missing data in several years are removed.Finally,a total of 382 samples are obtained.The R&D investment ratio,sales expense ratio,net interest rate of shareholders,the total assets of enterprises and enterprise asset-liability ratio are calculated respectively.

    3.3 Model building

    Based on the above assumptions,a linear regression equation is established between the independent and dependent variables as follows.

    Among them,the subscriptitindicates the financial index value of thei-th enterprise in the yeart,and ROE indicates the net interest rate of shareholders’ equity,which is used to show the ratio of net profit of thei-th enterprise in the yeartto the average owner’s equity.RDII indicates the proportion of R&D investment of the enterprise in the current year to gross profit.SALE indicates the proportion of sales expense of the enterprise in the current year to gross profit.SCALE is a measure of enterprise size,which is expressed by the total assets of the enterprise and is considered as a control variable in this model.DTAR indicates the asset-liability ratio of the enterprise,which is used by the enterprise to measure the proportion of funds from creditors among the funds required in the production and operation of the enterprise and is taken as a control variable in this model.εis a random error variable in the formula,as shown in Table 1.

    Table 1 Main indicators and their meanings

    3.4 Analysis of empirical results

    3.4.1 Descriptive statistics

    The data in 382 samples were statistically analyzed descriptively by SPSS 25,and the statistical results are shown in Table 2.

    Table 2 Descriptive statistics analysis

    It can be seen from the results that among the 382 samples selected by the biomedical enterprise,the minimum R&D investment ratio is 0.001%,while the maximum value reaches 65.99%,with the standard deviation of 8.40%.The large standard deviation of R&D investment ratio of biomedical enterprises indicates that the difference of R&D investment intensity is large,which may be caused by the difference of enterprise scales.Besides,the difference of R&D investment intensity might be caused by the different stages of enterprise life cycle.Secondly,the mean R&D investment ratio is 5.87%.The current study suggests that any pharmaceutical enterprise can maintain normal development when R&D expenditure reaches 2%,but it has a better market competitiveness only when it reaches 5%.Statistics show that the biomedical enterprises with an average value of 5.87% have a large R&D expenditure and core competitiveness.Thirdly,the minimum ration of sales expense is 0.002%,the maximum ration is 100.00%,and the mean value is 24.12%.The data statistics show that both the maximum value and the mean value are at a higher level.Fourth,the average net interest rate of shareholders is 11.12%,which is at a higher profit level in all industries.

    In summary,it can be concluded that the R&D expenditure,sales expenses and net interest rate of shareholders of biomedical listed enterprises in China are at a high level between 2015 and 2019,and all enterprises attach high importance to the investment in R&D and sales.

    3.4.2 Correlation analysis

    The data in the samples were analyzed by SPSS 25 for correlation,and the results are shown in Table 3.

    Table 3 Correlation coefficient between main indicators and significance

    Through the statistical results of SPSS 25 correlation,it can be seen that the correlation coefficient between R&D investment ratio and the net interest rate of shareholders is -0.430,and the significance test is passed,indicating that there is a significant correlation between the two.Therefore,it verifies hypothesis 1: R&D investment ratio is significantly negatively correlated with the net interest rate of shareholders of enterprises in the current period.The correlation coefficient between the sales expense ratio and the net interest rate of shareholders is 0.115,and the significance test is passed,which shows that there is a significant positive correlation between the two.Therefore,it verifies hypothesis 2:There is a significant positive correlation between the sales expense ratio and the net interest rate of shareholders of the enterprise in the current period.

    3.4.3 Multiple linear regression analysis

    Multiple linear regression analysis of the data by SPSS 25 showed the following results in Table 4 and Table 5.

    Table 4 Significance of linear regression equation

    Table 5 Regression coefficient of variables

    In the multiple linear regression analysis of the data by SPSS 25,Table 4 shows that the linear equation has a significant correlation due to itsFvalue of 25.076 and its significance is 0.000.The tolerance and variance inflation factor VIF can explain the collinear relationship between variables in collinearity test.When the tolerance in statistical results is less than 0.1 or the variance inflation factor is greater than 10,it means that there is obvious multicollinearity between R&D investment ratio,sales expense ratio,enterprise size,asset-liability ratio,and net interest rate of shareholders.Therefore,this regression equation cannot linearly reflect the relationship between independent variables and dependent variables.Table 5 displays that the tolerances in the collinearity statistics are all between 0.8 and 1,and the VIF coefficients between different variables are between 1.0 and 1.2,which are much less than 10,so there is no multicollinearity between the variables.The adjustedR2value of the equation was 0.202,indicating that the linear equation explained 20.20% of the relationship between variables.Bof R&D investment intensity is -0.510,while the significance is 0.000,so there is a significant negative correlation between R&D investment intensity and return on equity.Meanwhile,B of sales expense is 0.060,the significance is 0.024,so there is a significant positive correlation between sales expense and return on equity.

    4 Conclusion and suggestions

    4.1 Main conclusion

    Firstly,biomedical enterprises take new drug R&D as the core competitiveness.From the selected samples,although the overall level of absolute amount of R&D investment and sales expense is high,there is great difference among various enterprises.The correlation coefficient in the linear regression model in this paper also shows that there is a significant correlation between R&D investment,sales expense and the net interest rate of shareholders of enterprises.

    Secondly,the empirical research shows that there is a significant negative correlation between the R&D investment ratio and enterprise performance,but the samples with a large R&D investment ratio are mostly leading enterprises in the industry,with better performance in new drug R&D and patented drugs.The negative relationship between R&D investment and the performance of enterprises in the current period is due to the lag in the benefit of R&D expenditure.It means the current R&D investment only acts on a certain link in R&D that can produce a large benefit after the drug R&D is successful and approved for marketing.

    Thirdly,the empirical results show that there is a significant positive correlation between the sales expense ratio and enterprise performance,indicating that the sales of drugs by pharmaceutical enterprises is a direct source of enterprise performance.The largescale enterprises with more patents will invest more in the sales,and the enterprise performance will also be better.But the model shows that the coefficient B value of SALE in the equation is small,indicating that there is an unreasonable part of the sales expenses of biomedical enterprises.

    4.2 Suggestions

    Firstly,the development of biomedical enterprises is based on the continuous successful innovation and production of new drugs.No matter whether they are used as treatment or prevention,R&D must ensure the market demand,which can guarantee the products to obtain sales and profits proportional to the investment.Therefore,the selection of appropriate R&D strategy is an important management activity of enterprises.Therefore,enterprises need to strictly control the management of advance,in-process and afterwards results of R&D in combination with their industrial status and the actual situation of internal capital,arranging budget investment reasonably and improving the capitalization level,maximizing the negative impact of fund outflow on the performance,and improving the competitiveness to have a sustainable development.

    Secondly,because the R&D investment of enterprises in the model has a negative correlation with the net interest rate of shareholders of enterprises,the conclusion is also in line with the intuitive perception of management on business data.If only short-term interests are considered and corresponding R&D investment plans are formulated conservatively,it will affect the long-term competitiveness of enterprises,and ultimately cause R&D and innovation capacity in China’s enterprises to lag far behind compared with developed countries.It is obviously not conducive to the healthy development of the industry.In view of the current situation,the government should give play to the regulatory role of “tangible hands” in the market,improving the patent protection system,strengthening the protection period and intensity of innovative products developed by enterprises,and giving subsidies and honorary rewards to high-quality products.In addition,it should intensify support in terms of policies,subsidizing enterprises,and allowing enterprises to invest manpower and material resources to focus on R&D and innovation.

    Thirdly,drug development aims to meet the needs of people who do not have access to appropriate therapeutic agents to prevent various diseases.Under the premise of market demand,the marketing should solve the matching problem between drug R&D and market demand,which also helps biomedical enterprises obtain profits.The research results show that,within the allowable range,improving the sales expenses of enterprises can positively promote the performance of enterprises.Therefore,it is necessary to increase the capital investment of sales departments,which can maintain the sales channels,strengthen the knowledge training of sales personnel and improve the sales incentive mechanism of enterprises.In addition,it is vital to build new sales channels to attract more customers.The upstream and downstream highquality enterprises can cooperate to establish win-win partnerships so that they will invest the sales expenses in the projects that have the greatest impact on the performance of enterprises.

    Fourthly,the R&D and the sales are two crucial links for the survival and development of biomedical enterprises,and they are closely related.On the one hand,the capital arrangement of enterprises may limit the investment of the two.On the other hand,the R&D investment will be more conducive to the long-term development of enterprises because of its delayed benefits,which is necessary for the sustainable growth of enterprises.However,the sales expense is directly conducive to the enterprise performance,so the formulation of budget planning becomes a key strategy of enterprises.For enterprises with a certain scale,it is necessary to reasonably arrange the investment ratio between R&D investment and the sales expense,which can ensure the long-term development of enterprises.

    一区二区三区激情视频| 国产成人一区二区三区免费视频网站| 亚洲,欧美精品.| 神马国产精品三级电影在线观看 | 国产成人影院久久av| 国产欧美日韩一区二区精品| 国产亚洲av嫩草精品影院| 制服丝袜大香蕉在线| 中文字幕人妻丝袜一区二区| 香蕉丝袜av| 在线观看日韩欧美| 亚洲国产中文字幕在线视频| 午夜日韩欧美国产| 日本vs欧美在线观看视频| av超薄肉色丝袜交足视频| 国产色视频综合| 少妇的丰满在线观看| 窝窝影院91人妻| 成人精品一区二区免费| 国产激情欧美一区二区| 欧美 亚洲 国产 日韩一| 日韩中文字幕欧美一区二区| 不卡一级毛片| 精品电影一区二区在线| 在线视频色国产色| 国产91精品成人一区二区三区| 精品乱码久久久久久99久播| 一进一出好大好爽视频| 久久久久久久午夜电影| 亚洲精华国产精华精| 免费在线观看黄色视频的| 91麻豆av在线| 人妻丰满熟妇av一区二区三区| 国产1区2区3区精品| 日韩大尺度精品在线看网址 | 一二三四社区在线视频社区8| 亚洲久久久国产精品| 国产精品自产拍在线观看55亚洲| 久久久久久久精品吃奶| 色综合欧美亚洲国产小说| 午夜福利影视在线免费观看| 男女下面进入的视频免费午夜 | 亚洲人成电影观看| 啦啦啦观看免费观看视频高清 | 日本vs欧美在线观看视频| 热re99久久国产66热| 亚洲专区中文字幕在线| 极品教师在线免费播放| 久久久久国产一级毛片高清牌| 女人爽到高潮嗷嗷叫在线视频| 久久欧美精品欧美久久欧美| 99国产综合亚洲精品| aaaaa片日本免费| 波多野结衣巨乳人妻| 悠悠久久av| 亚洲av成人av| 三级毛片av免费| 麻豆一二三区av精品| 一进一出抽搐gif免费好疼| 88av欧美| x7x7x7水蜜桃| 亚洲最大成人中文| 一区福利在线观看| 亚洲av熟女| 老司机午夜福利在线观看视频| 国产成+人综合+亚洲专区| 欧美日本亚洲视频在线播放| 香蕉丝袜av| 精品久久蜜臀av无| 变态另类成人亚洲欧美熟女 | 啦啦啦韩国在线观看视频| 久久婷婷成人综合色麻豆| www.999成人在线观看| 亚洲成av人片免费观看| 波多野结衣巨乳人妻| 神马国产精品三级电影在线观看 | 美女免费视频网站| 亚洲av五月六月丁香网| 久久影院123| 久久青草综合色| 日日夜夜操网爽| 一本大道久久a久久精品| 一边摸一边抽搐一进一出视频| 久久国产精品影院| 国产亚洲精品久久久久久毛片| 欧美一区二区精品小视频在线| 无遮挡黄片免费观看| 国产欧美日韩一区二区三| 99在线人妻在线中文字幕| 久久亚洲真实| 国产成人av教育| 日本一区二区免费在线视频| 久久天堂一区二区三区四区| 日韩欧美三级三区| 女生性感内裤真人,穿戴方法视频| 香蕉丝袜av| 在线观看日韩欧美| 在线播放国产精品三级| 欧美乱色亚洲激情| 伊人久久大香线蕉亚洲五| 国产精品久久久人人做人人爽| 露出奶头的视频| 大型av网站在线播放| 久久香蕉激情| 老司机午夜福利在线观看视频| 亚洲欧洲精品一区二区精品久久久| 超碰成人久久| 精品国产一区二区三区四区第35| 给我免费播放毛片高清在线观看| 看黄色毛片网站| 精品人妻1区二区| 51午夜福利影视在线观看| 亚洲avbb在线观看| 亚洲精品中文字幕在线视频| 午夜亚洲福利在线播放| xxx96com| 亚洲少妇的诱惑av| 免费搜索国产男女视频| 伦理电影免费视频| 9热在线视频观看99| 欧美日韩黄片免| 变态另类成人亚洲欧美熟女 | 久久人人精品亚洲av| 国产一区二区在线av高清观看| 中文字幕另类日韩欧美亚洲嫩草| 多毛熟女@视频| 国产成人欧美在线观看| 91大片在线观看| 精品卡一卡二卡四卡免费| 亚洲精品一卡2卡三卡4卡5卡| 精品久久久久久,| 国产精品免费一区二区三区在线| 久久久久久国产a免费观看| 午夜免费激情av| 成人三级做爰电影| 中文亚洲av片在线观看爽| 精品人妻1区二区| 国产精品爽爽va在线观看网站 | 日本 欧美在线| 天堂影院成人在线观看| www.自偷自拍.com| 免费人成视频x8x8入口观看| 久久久久国产一级毛片高清牌| 久久精品亚洲精品国产色婷小说| 亚洲中文字幕一区二区三区有码在线看 | 在线观看日韩欧美| 久久伊人香网站| 国产熟女xx| 亚洲一区二区三区色噜噜| 亚洲成人国产一区在线观看| 日韩有码中文字幕| 曰老女人黄片| 国产精品爽爽va在线观看网站 | 50天的宝宝边吃奶边哭怎么回事| 色在线成人网| 香蕉国产在线看| 精品高清国产在线一区| 色综合亚洲欧美另类图片| 久久香蕉激情| 在线十欧美十亚洲十日本专区| 黄色女人牲交| x7x7x7水蜜桃| 亚洲国产高清在线一区二区三 | 69av精品久久久久久| 午夜久久久久精精品| 一区二区三区高清视频在线| 91av网站免费观看| 精品久久久久久久久久免费视频| 亚洲精品一区av在线观看| 欧美在线一区亚洲| 精品一区二区三区av网在线观看| 美女大奶头视频| 丝袜人妻中文字幕| 女人爽到高潮嗷嗷叫在线视频| 久久婷婷人人爽人人干人人爱 | 国产成人系列免费观看| 真人一进一出gif抽搐免费| 国产亚洲精品av在线| 欧美黑人精品巨大| 99精品久久久久人妻精品| 搞女人的毛片| 日韩欧美三级三区| 欧美日韩亚洲国产一区二区在线观看| 18禁观看日本| 又大又爽又粗| 99国产精品一区二区三区| 国产91精品成人一区二区三区| 非洲黑人性xxxx精品又粗又长| 色老头精品视频在线观看| 日韩欧美三级三区| 国产精品久久电影中文字幕| 久久人人97超碰香蕉20202| 日日干狠狠操夜夜爽| 国产成人av激情在线播放| 91成人精品电影| 中国美女看黄片| 一区二区三区国产精品乱码| 男女下面进入的视频免费午夜 | 亚洲欧美精品综合久久99| 国产午夜福利久久久久久| 免费看美女性在线毛片视频| 中文字幕av电影在线播放| 久久国产精品男人的天堂亚洲| 给我免费播放毛片高清在线观看| 国产成+人综合+亚洲专区| 精品乱码久久久久久99久播| 精品欧美一区二区三区在线| 久久久久亚洲av毛片大全| 免费搜索国产男女视频| 国产精品亚洲美女久久久| 欧美黄色片欧美黄色片| 美女扒开内裤让男人捅视频| 精品人妻1区二区| 丝袜人妻中文字幕| 午夜福利影视在线免费观看| 国产三级黄色录像| 久久人妻av系列| 亚洲av成人不卡在线观看播放网| 欧美在线一区亚洲| 精品国产国语对白av| 国产欧美日韩一区二区三| 亚洲成a人片在线一区二区| 精品少妇一区二区三区视频日本电影| 少妇裸体淫交视频免费看高清 | 操出白浆在线播放| 女同久久另类99精品国产91| 日本免费a在线| 亚洲情色 制服丝袜| 久久人人精品亚洲av| 给我免费播放毛片高清在线观看| 欧美精品亚洲一区二区| 欧美日韩乱码在线| 国产成人av激情在线播放| 亚洲专区中文字幕在线| 黄色视频,在线免费观看| 热99re8久久精品国产| 亚洲国产欧美网| 老熟妇仑乱视频hdxx| 老汉色av国产亚洲站长工具| 国产亚洲av嫩草精品影院| 国产成人av激情在线播放| 国产精品99久久99久久久不卡| 国产精品久久久久久精品电影 | 操出白浆在线播放| 成人永久免费在线观看视频| 久久精品aⅴ一区二区三区四区| 在线观看日韩欧美| 妹子高潮喷水视频| 亚洲精品久久国产高清桃花| 不卡av一区二区三区| 日韩三级视频一区二区三区| 久久久久久久久免费视频了| 精品国产美女av久久久久小说| 日韩一卡2卡3卡4卡2021年| 午夜两性在线视频| 久久精品91无色码中文字幕| www日本在线高清视频| 欧美激情极品国产一区二区三区| 午夜成年电影在线免费观看| 欧美在线黄色| 欧美色欧美亚洲另类二区 | cao死你这个sao货| av天堂久久9| 亚洲avbb在线观看| 一边摸一边做爽爽视频免费| 宅男免费午夜| 欧美成人一区二区免费高清观看 | 欧美精品亚洲一区二区| 精品乱码久久久久久99久播| 色综合欧美亚洲国产小说| 成人国产一区最新在线观看| 中文字幕人妻熟女乱码| 亚洲欧美日韩另类电影网站| 亚洲国产精品成人综合色| 色播在线永久视频| 国产黄a三级三级三级人| 国产精品 欧美亚洲| 精品久久久久久,| 免费在线观看黄色视频的| 午夜两性在线视频| www.www免费av| 国产精品国产高清国产av| 久久久久久大精品| 国产成人免费无遮挡视频| 午夜免费观看网址| 亚洲精品国产色婷婷电影| 成人三级黄色视频| 亚洲免费av在线视频| 国产精品综合久久久久久久免费 | 亚洲最大成人中文| 久久人妻熟女aⅴ| 99国产精品99久久久久| 国产亚洲欧美在线一区二区| 日日爽夜夜爽网站| 亚洲av成人av| 人人澡人人妻人| 丰满的人妻完整版| 日本三级黄在线观看| 亚洲欧美日韩无卡精品| 日本vs欧美在线观看视频| 一进一出抽搐gif免费好疼| 男人的好看免费观看在线视频 | av电影中文网址| 国产午夜精品久久久久久| 国产精品一区二区在线不卡| 色综合亚洲欧美另类图片| 成人三级做爰电影| 亚洲美女黄片视频| 欧美丝袜亚洲另类 | 精品日产1卡2卡| 乱人伦中国视频| 免费在线观看黄色视频的| 国产一级毛片七仙女欲春2 | 啦啦啦观看免费观看视频高清 | 色播在线永久视频| 国产一区二区三区在线臀色熟女| 色播在线永久视频| 成在线人永久免费视频| 搡老熟女国产l中国老女人| 变态另类丝袜制服| 黄色毛片三级朝国网站| 久久久久久久午夜电影| 亚洲中文日韩欧美视频| 成人免费观看视频高清| 丝袜美足系列| 亚洲无线在线观看| 9191精品国产免费久久| 久久中文字幕人妻熟女| 久久国产亚洲av麻豆专区| 免费高清视频大片| 制服人妻中文乱码| 国产私拍福利视频在线观看| 欧洲精品卡2卡3卡4卡5卡区| 国产精品久久久人人做人人爽| 亚洲精品国产一区二区精华液| 丁香欧美五月| 成年女人毛片免费观看观看9| 国产三级在线视频| e午夜精品久久久久久久| 国产精品久久久久久亚洲av鲁大| 国产精品秋霞免费鲁丝片| 丝袜在线中文字幕| 可以在线观看的亚洲视频| 欧美亚洲日本最大视频资源| 好男人在线观看高清免费视频 | АⅤ资源中文在线天堂| 看免费av毛片| 变态另类丝袜制服| 男男h啪啪无遮挡| 亚洲熟妇熟女久久| 波多野结衣巨乳人妻| 19禁男女啪啪无遮挡网站| 精品久久久久久久久久免费视频| 亚洲av成人av| 免费一级毛片在线播放高清视频 | 亚洲最大成人中文| 亚洲国产精品成人综合色| 日韩精品中文字幕看吧| cao死你这个sao货| 一级a爱视频在线免费观看| cao死你这个sao货| 久久国产精品影院| 国产色视频综合| 在线观看www视频免费| 一本久久中文字幕| 不卡一级毛片| 国产极品粉嫩免费观看在线| 黑人巨大精品欧美一区二区蜜桃| e午夜精品久久久久久久| 亚洲精品一区av在线观看| aaaaa片日本免费| 午夜免费成人在线视频| 性少妇av在线| 国产精品久久久av美女十八| 亚洲男人的天堂狠狠| 欧美黑人精品巨大| 91大片在线观看| 日韩欧美三级三区| 窝窝影院91人妻| 亚洲中文av在线| 亚洲中文日韩欧美视频| 日韩欧美免费精品| 一边摸一边抽搐一进一出视频| cao死你这个sao货| 在线观看免费视频日本深夜| 大香蕉久久成人网| 黄色 视频免费看| 亚洲人成电影免费在线| 日韩精品青青久久久久久| 亚洲人成伊人成综合网2020| 免费看a级黄色片| 女人被狂操c到高潮| 亚洲第一av免费看| 国产成人啪精品午夜网站| 久久亚洲精品不卡| 欧美成人免费av一区二区三区| 成人国产一区最新在线观看| 91国产中文字幕| 国产精品亚洲美女久久久| 男女床上黄色一级片免费看| 精品久久蜜臀av无| 少妇粗大呻吟视频| av超薄肉色丝袜交足视频| av电影中文网址| 变态另类丝袜制服| 日韩欧美国产在线观看| 久久久国产欧美日韩av| 好男人在线观看高清免费视频 | 每晚都被弄得嗷嗷叫到高潮| 亚洲国产欧美一区二区综合| 在线观看舔阴道视频| www.999成人在线观看| 国产精品 欧美亚洲| 国产野战对白在线观看| 日本一区二区免费在线视频| 夜夜看夜夜爽夜夜摸| 亚洲国产精品成人综合色| 好看av亚洲va欧美ⅴa在| 91精品三级在线观看| 日韩欧美在线二视频| 亚洲成人精品中文字幕电影| 日本一区二区免费在线视频| 精品国产亚洲在线| 久久精品91无色码中文字幕| 少妇熟女aⅴ在线视频| 成在线人永久免费视频| 91精品国产国语对白视频| 欧美激情 高清一区二区三区| 国产亚洲欧美精品永久| 黑人巨大精品欧美一区二区蜜桃| 制服诱惑二区| 亚洲av五月六月丁香网| 免费观看人在逋| 亚洲成人精品中文字幕电影| 国产麻豆成人av免费视频| 成人av一区二区三区在线看| 国内毛片毛片毛片毛片毛片| 他把我摸到了高潮在线观看| 麻豆国产av国片精品| 欧美日韩黄片免| 十八禁人妻一区二区| 淫妇啪啪啪对白视频| 自线自在国产av| 亚洲成av人片免费观看| 黑人巨大精品欧美一区二区mp4| 日本免费a在线| 丝袜美足系列| 变态另类丝袜制服| 9色porny在线观看| 丰满的人妻完整版| 国产精品永久免费网站| 亚洲欧美精品综合久久99| 黄色丝袜av网址大全| 在线观看一区二区三区| 夜夜夜夜夜久久久久| 日韩免费av在线播放| 亚洲五月婷婷丁香| 亚洲国产精品合色在线| 久久中文字幕一级| 欧美日本视频| 黄色视频不卡| 国产精品一区二区免费欧美| 久久精品国产亚洲av香蕉五月| 国产单亲对白刺激| 久久欧美精品欧美久久欧美| 免费在线观看黄色视频的| 国产99白浆流出| 亚洲五月婷婷丁香| 精品不卡国产一区二区三区| 午夜福利视频1000在线观看 | 大香蕉久久成人网| 亚洲伊人色综图| 校园春色视频在线观看| 欧美黄色片欧美黄色片| 亚洲国产日韩欧美精品在线观看 | 成人18禁在线播放| 国产精品九九99| 美国免费a级毛片| 久久亚洲真实| 日韩免费av在线播放| 中文字幕色久视频| 88av欧美| 久久精品亚洲精品国产色婷小说| 久久久久国内视频| 欧美+亚洲+日韩+国产| 老司机午夜福利在线观看视频| 亚洲激情在线av| 99国产精品99久久久久| 亚洲黑人精品在线| 老熟妇仑乱视频hdxx| 中文字幕色久视频| 国产成年人精品一区二区| 91在线观看av| 久久久久国内视频| 亚洲伊人色综图| 国产精品 欧美亚洲| 日韩三级视频一区二区三区| 757午夜福利合集在线观看| 成人手机av| 午夜影院日韩av| svipshipincom国产片| 国产午夜精品久久久久久| 欧美国产精品va在线观看不卡| 亚洲aⅴ乱码一区二区在线播放 | 亚洲专区国产一区二区| 国产麻豆成人av免费视频| 国产又色又爽无遮挡免费看| 欧美一级a爱片免费观看看 | videosex国产| 9热在线视频观看99| 99香蕉大伊视频| 亚洲第一av免费看| 日韩大尺度精品在线看网址 | 动漫黄色视频在线观看| 在线av久久热| 日韩欧美三级三区| 又黄又粗又硬又大视频| 男人的好看免费观看在线视频 | 精品电影一区二区在线| 美女扒开内裤让男人捅视频| 久久香蕉国产精品| 777久久人妻少妇嫩草av网站| 亚洲人成电影免费在线| 久久亚洲精品不卡| 亚洲中文日韩欧美视频| 18美女黄网站色大片免费观看| 欧美+亚洲+日韩+国产| 多毛熟女@视频| 视频区欧美日本亚洲| 激情在线观看视频在线高清| 可以在线观看的亚洲视频| 午夜a级毛片| 免费一级毛片在线播放高清视频 | 老熟妇仑乱视频hdxx| 色av中文字幕| 国产三级黄色录像| 亚洲欧美精品综合一区二区三区| 一进一出抽搐动态| 男女做爰动态图高潮gif福利片 | 长腿黑丝高跟| 激情在线观看视频在线高清| 18禁黄网站禁片午夜丰满| 婷婷六月久久综合丁香| 国产亚洲精品综合一区在线观看 | 亚洲精品中文字幕一二三四区| 亚洲精品国产区一区二| 精品久久蜜臀av无| 在线天堂中文资源库| 一边摸一边抽搐一进一出视频| 在线观看日韩欧美| 久热这里只有精品99| 色综合婷婷激情| 日韩高清综合在线| 精品久久久久久,| 怎么达到女性高潮| 亚洲黑人精品在线| 久久久久亚洲av毛片大全| 久久午夜综合久久蜜桃| 国产精品av久久久久免费| 亚洲欧美激情在线| 最新在线观看一区二区三区| 99国产精品免费福利视频| 又黄又爽又免费观看的视频| bbb黄色大片| 欧美午夜高清在线| 国产熟女xx| 亚洲人成电影观看| 一级a爱片免费观看的视频| 亚洲色图综合在线观看| 电影成人av| 99国产极品粉嫩在线观看| 日韩欧美国产在线观看| 免费女性裸体啪啪无遮挡网站| 老汉色∧v一级毛片| 欧美日韩亚洲国产一区二区在线观看| videosex国产| 成人特级黄色片久久久久久久| 可以免费在线观看a视频的电影网站| 在线观看免费视频网站a站| 久久影院123| 国产一区二区激情短视频| 咕卡用的链子| av视频在线观看入口| 久热爱精品视频在线9| 最近最新免费中文字幕在线| 女同久久另类99精品国产91| 欧美人与性动交α欧美精品济南到| 嫩草影视91久久| 精品欧美一区二区三区在线| 亚洲五月色婷婷综合| 色综合婷婷激情| 最近最新中文字幕大全免费视频| 少妇 在线观看| 日韩有码中文字幕| 国产真人三级小视频在线观看| 欧美中文综合在线视频| 久久精品影院6| 亚洲va日本ⅴa欧美va伊人久久| 色播亚洲综合网| 亚洲精品在线美女| 国产国语露脸激情在线看| 亚洲自拍偷在线| 国产激情久久老熟女| 宅男免费午夜| 中文字幕高清在线视频| 男女之事视频高清在线观看| 麻豆成人av在线观看| 日本一区二区免费在线视频| 在线视频色国产色| 91大片在线观看| 90打野战视频偷拍视频| 少妇熟女aⅴ在线视频| 男人的好看免费观看在线视频 | 制服人妻中文乱码| 国产成人精品在线电影|