• <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 ?

    Legacy Information Technology Compounds Pandemic Pain

    2021-08-30 07:05:42MitchLeslie
    Engineering 2021年4期

    Mitch Leslie

    Senior Technology Writer

    When the coronavirus disease 2019(COVID-19)pandemic exploded in the United States in March 2020,the US Congress passed a bill to provide extra unemployment benefits to the record numbers of people who had lost their jobs.The task of disbursing the money fell to the individual states,but in more than 20 of them,aged computer systems struggled to handle the surge in claims,delaying payments to many financially strapped residents by weeks and even months[1,2].

    In the state of California,USA,a team of expert investigators found that although the employment department’s information technology(IT)system—the core of which is an International Business Machines Corporation(IBM)mainframe computer—performed fairly well,it was partly to blame for the delays,which were some of the longest in the nation.The system’s limitations slowed payments and complicated the unemployment claims process in several ways[3].For instance,even making claims was difficult for many,because the filing website was not compatible with mobile phones or accessible by people with disabilities[3].And the field for home address in the database that records applicants’information was too short,so claims from people with long addresses required slower manual processing.

    The difficulties many US states encountered with their unemployment payments highlight how old,clunky,and inefficient many essential IT systems are.Aged IT systems are also to blame for a large share of banking outages,airline delays,and security breaches[2].‘‘These problems are constant,”said David Eaves,a lecturer in public policy at Harvard University in Cambridge,MA,USA.‘‘Our track record at modernizing is very poor.”

    Yet there is no simple remedy for outdated IT.Replacing or renovating legacy hardware and software is expensive,timeconsuming,and risky.One survey of corporate leaders found that 74%of IT upgrades at their companies had failed[4].Some novel approaches,such as deploying artificial intelligence(AI)to revamp outmoded software[5],may make overhauls easier.But in some cases,‘‘the systems reach a size when they cannot be modernized,”said Harry Sneed,an assistant professor of software engineering at Dresden University of Technology in Germany.

    Experts have long warned about the problem of aging IT.A 2016 report by the US Government Accountability Office(GAO)identified the ten systems at federal agencies that most needed upgrading[6].The Department of the Treasury’s master files that hold data on US taxpayers and businesses,which are now more than 60 years old,were the most ancient.But the most disturbing example came from the Department of Defense,which controlled the country’s nuclear weapons with the help of a 1970s IBM Series/1 computer(Fig.1)that still used 8 in(1 in=2.54 cm)floppy disks[7].

    That system has since been revamped so that it no longer requires the long-obsolete disks(Fig.2)[8],and the Department of the Treasury is now updating its taxpayer records[9].Still,the most recent edition of the GAO report,published in 2019,identified another six vital federal government systems that were more than 30 years old[10].

    Other examples of legacy IT abound.The world’s financial system depends on the programming common business oriented language(COBOL),which handles 95%of automatic teller machine transactions[11].The language was introduced in 1959,and many of the programmers who know it are about the same vintage—their average age is now around 60,although interest in COBOL has recently surged[1,12].And Japan’s government is so reliant on out-of-date technology,including fax machines,that it recently launched a new agency to speed modernization[13].

    There are numerous reasons to replace elderly technologies.For one thing,old systems are expensive to run.In 2019,the US government spent more than 80%of its IT budget of roughly 90 billion USD to maintain existing systems,many of which are legacy technology[10].Old hardware is slow and lacks modern capabilities.Dinosaur machines like the IBMSeries/1 at the Department of Defense have far less computing power than a single modern smart phone[14].As the recent state unemployment pandemic-related problems revealed,aged systems can also be less flexible during a crisis.In 2017,the state of Massachusetts shifted its unemployment system to the cloud,allowing it to respond faster when COVID-19 put many people out of work[15].States are required to deliver recipients’first payments within three weeks,and Massachusetts met that deadline 68%of the time,whereas Florida,which was using older technology,succeeded only 28%of the time in the first months of the pandemic[15].

    Fig.1.The US Department of Defense uses an IBM Series/1 computer from the 1970s to help control the country’s nuclear arsenal.Until 2019,the computer still needed 8 in floppy disks.Credit:US GAO(public domain).

    Fig.2.Now legacy technology,the 8 in floppy disk(rear)was an information storage breakthrough,holding 80 kb of data,when it was commercially introduced in 1971.Its 1980s successor,the 3.5 in floppy disk(left),is now also obsolete,replaced by universal serial bus(USB)data keys(bottom right)that today can hold many gigabytes of data.Credit:Wikimedia(public domain).

    Modernizing out-of-date systems seems like an obvious strategy,yet organizations often stick with legacy tech.One reason is that,in many cases,it still does the job.‘‘There are billions of lines of code that work,day in and day out,”said Jon Pyke,chief executive officer of the software upgrade company CIMtrek in Woodham Surrey,UK.‘‘Only when unprecedented events occur do things fall apart.”Moreover,users are often more productive with a mature system they are familiar with,said Sneed.

    But probably the biggest reason aged IT systems remain in operation is the many obstacles that block their modernization or replacement[2].The costs to upgrade are often prohibitive,the work can be disruptive,and the odds of success are low.In addition,corporations and governments often lack incentive to begin these projects,said Eaves.For example,politicians are reluctant to push for overhauls of government systems,he said.Given that many upgrades take more than a decade,they know that they probably will‘‘not get the credit or benefit but will face the criticism for delays or failure.”IT managers can be similarly hesitant to back upgrade projects,Sneed said.‘‘Their jobs are on the line.”

    The complexity of legacy systems also makes them difficult to overhaul.Software provides a good example.Much of the world’s legacy code is a mess,said Sneed,who has worked on more than 70 software modernization projects for private and public sector clients,including Volkswagen and Swiss Bank.Over the years,many software systems have grown to enormous size,and they are riddled with non-functional or redundant code.Between 1979 and 2017,one of Sneed’s corporate clients saw its software system expand from 2 million lines to 11 million lines.A related problem is poor documentation.Sneed recalled that almost every organization he consulted for had‘‘a(chǎn) room full of dusty notebooks”that supposedly recorded how its software operated.But these records were rarely up to date,and the original programmers had usually departed by the time an upgrade was under consideration.

    One solution for problematic code,according to Sneed,is to replace it with off-the-shelf,purpose-written software.These programs can be cumbersome,however,and often‘‘users are forced to work around them instead of with them,”he noted.Organizations may also decide to retain the original software and add a new interface that provides capabilities today’s users expect,such as friendly,graphics-based access.But this option does not correct any problems of the underlying system.In the end,rewriting ancient code may be the‘‘least bad”option,Sneed concluded.But before programmers can recast old software in a modern language,they may have to analyze millions of lines of code to figure out how it works and what functions it enables.Revising old software is such an enormous task that computer giant IBM has its Watson AI system working on the problem[5].

    Despite all the obstacles,there are some IT modernization success stories.For example,the northeastern European country Estonia has received praise for adopting a smart IT strategy[16].The country had to start from scratch when it became independent in the early 1990s,allowing it to be more innovative.Taking a preventive approach to legacy IT,Estonia replaces all critical systems before they are 13 years old[16].For some organizations,an agile approach,in which they develop and roll out modules that perform certain operations,may work better than organizing an upgrade as a massive project with a single launch,said Eaves.The latter‘‘waterfall”projects‘‘have a high propensity for failure,”he said.

    Although the unemployment crisis triggered by COVID-19 continues,some out-of-work people are seeing the benefits of IT upgrades.In January 2020,the state of Colorado launched its modernized system,which for the first time will allow the state to communicate with recipients through e-mails or texts[17,18].But other beneficiaries will have longer to wait.Oregon,the last US state to send out supplementary unemployment payments in 2020,has only just begun to upgrade its system,with the new version not expected online until at least 2025[19].

    精华霜和精华液先用哪个| 777米奇影视久久| 亚洲av不卡在线观看| 日产精品乱码卡一卡2卡三| 好男人在线观看高清免费视频| 免费大片黄手机在线观看| 天美传媒精品一区二区| 青春草视频在线免费观看| 菩萨蛮人人尽说江南好唐韦庄| 亚洲成人一二三区av| 午夜日本视频在线| 国产黄色视频一区二区在线观看| 免费观看av网站的网址| 一区二区三区免费毛片| 国产精品一区二区在线观看99 | 在线观看美女被高潮喷水网站| 国产亚洲精品av在线| 精品一区在线观看国产| 人人妻人人看人人澡| 男女国产视频网站| 亚洲三级黄色毛片| 国产精品一及| 免费少妇av软件| 国产男人的电影天堂91| 亚洲在线自拍视频| 一本—道久久a久久精品蜜桃钙片 精品乱码久久久久久99久播 | 91久久精品电影网| 国产精品美女特级片免费视频播放器| 亚洲精品aⅴ在线观看| 国产精品久久久久久精品电影小说 | 国产淫片久久久久久久久| 国产精品久久久久久久电影| 成人无遮挡网站| 国产有黄有色有爽视频| 在现免费观看毛片| 日本黄大片高清| 国产黄色视频一区二区在线观看| 日产精品乱码卡一卡2卡三| 夫妻性生交免费视频一级片| 22中文网久久字幕| 搞女人的毛片| 中文字幕人妻熟人妻熟丝袜美| av女优亚洲男人天堂| 一个人免费在线观看电影| 三级经典国产精品| 精品一区二区三区视频在线| 只有这里有精品99| 免费黄网站久久成人精品| 日韩三级伦理在线观看| 欧美变态另类bdsm刘玥| 国产黄色小视频在线观看| 黄色配什么色好看| 丰满少妇做爰视频| 精品一区在线观看国产| 男女国产视频网站| 又大又黄又爽视频免费| 精品不卡国产一区二区三区| 黄色欧美视频在线观看| 成年免费大片在线观看| 亚洲最大成人av| 免费无遮挡裸体视频| 亚洲欧美清纯卡通| 男人舔奶头视频| 国产单亲对白刺激| 国产成人免费观看mmmm| 大又大粗又爽又黄少妇毛片口| 男女国产视频网站| 老司机影院毛片| 久久久久精品性色| 国产精品国产三级专区第一集| 中文字幕亚洲精品专区| 欧美极品一区二区三区四区| 26uuu在线亚洲综合色| 内地一区二区视频在线| 少妇的逼好多水| 亚洲欧美日韩东京热| 午夜免费激情av| 亚洲精品久久久久久婷婷小说| 日韩av免费高清视频| 亚洲在线自拍视频| 超碰av人人做人人爽久久| 亚洲成人av在线免费| 高清欧美精品videossex| 日韩av不卡免费在线播放| 午夜精品国产一区二区电影 | 欧美日韩亚洲高清精品| 在线免费观看的www视频| 97超碰精品成人国产| 久久午夜福利片| 午夜福利在线在线| 亚洲一区高清亚洲精品| 一级毛片 在线播放| 中文字幕久久专区| 久久韩国三级中文字幕| 欧美精品一区二区大全| 国产精品伦人一区二区| 菩萨蛮人人尽说江南好唐韦庄| 久久久久久久久中文| 欧美xxxx黑人xx丫x性爽| 日韩人妻高清精品专区| 18禁动态无遮挡网站| 少妇的逼好多水| .国产精品久久| 久久精品国产亚洲网站| 国产精品人妻久久久影院| 日韩国内少妇激情av| 好男人在线观看高清免费视频| 精品久久久久久久久亚洲| 亚洲av中文字字幕乱码综合| 欧美成人a在线观看| 亚洲激情五月婷婷啪啪| 国产乱人偷精品视频| 国产黄色小视频在线观看| 精品人妻偷拍中文字幕| 别揉我奶头 嗯啊视频| 99九九线精品视频在线观看视频| 夜夜看夜夜爽夜夜摸| 国产精品蜜桃在线观看| 欧美另类一区| 永久网站在线| 日本三级黄在线观看| 超碰av人人做人人爽久久| 我的老师免费观看完整版| 伊人久久精品亚洲午夜| 1000部很黄的大片| 亚洲成人精品中文字幕电影| 老司机影院毛片| 啦啦啦啦在线视频资源| 2018国产大陆天天弄谢| 成人高潮视频无遮挡免费网站| 国产精品一区www在线观看| www.色视频.com| 高清视频免费观看一区二区 | 伦精品一区二区三区| 国产精品久久久久久精品电影小说 | 久久99蜜桃精品久久| 国产色婷婷99| 丝袜美腿在线中文| 国产精品一区www在线观看| 国产亚洲精品久久久com| av在线播放精品| 亚洲国产欧美人成| 日韩欧美国产在线观看| 午夜精品国产一区二区电影 | 在线a可以看的网站| 久久久久久久大尺度免费视频| 一级二级三级毛片免费看| 久久久亚洲精品成人影院| 成人欧美大片| 简卡轻食公司| 国产欧美另类精品又又久久亚洲欧美| av福利片在线观看| 久久精品国产鲁丝片午夜精品| 国产综合懂色| a级一级毛片免费在线观看| 久久久久久久亚洲中文字幕| 日本三级黄在线观看| 18禁动态无遮挡网站| 男人狂女人下面高潮的视频| 成人亚洲精品av一区二区| 99久久精品国产国产毛片| 国产精品人妻久久久影院| 国产精品一区二区性色av| 欧美一级a爱片免费观看看| 亚洲综合精品二区| 丰满人妻一区二区三区视频av| 你懂的网址亚洲精品在线观看| 国产亚洲av片在线观看秒播厂 | 国产片特级美女逼逼视频| 午夜激情久久久久久久| 永久免费av网站大全| 日韩视频在线欧美| 成人av在线播放网站| 国产成人精品婷婷| 久久热精品热| 中文字幕av在线有码专区| 99热6这里只有精品| 国产视频首页在线观看| 亚洲精品,欧美精品| 国产探花极品一区二区| 欧美成人精品欧美一级黄| 69av精品久久久久久| 婷婷色综合大香蕉| 国产探花极品一区二区| av在线播放精品| av在线蜜桃| 黄色欧美视频在线观看| 国产精品美女特级片免费视频播放器| av一本久久久久| 国产午夜精品久久久久久一区二区三区| kizo精华| 亚洲av不卡在线观看| 性插视频无遮挡在线免费观看| 久久久成人免费电影| 全区人妻精品视频| 啦啦啦韩国在线观看视频| 乱系列少妇在线播放| 国产亚洲最大av| 自拍偷自拍亚洲精品老妇| 内射极品少妇av片p| 欧美高清性xxxxhd video| 一级毛片我不卡| 日韩欧美三级三区| 国内精品美女久久久久久| 亚洲丝袜综合中文字幕| 99热全是精品| 少妇猛男粗大的猛烈进出视频 | 国产有黄有色有爽视频| 午夜免费观看性视频| 国产精品国产三级国产专区5o| 午夜亚洲福利在线播放| 久久精品夜夜夜夜夜久久蜜豆| 国产白丝娇喘喷水9色精品| 国产乱人偷精品视频| 男人爽女人下面视频在线观看| 国产视频首页在线观看| 久久精品国产自在天天线| 国产精品久久久久久久电影| 欧美一级a爱片免费观看看| 国产中年淑女户外野战色| 一夜夜www| 我的女老师完整版在线观看| 成人特级av手机在线观看| 久久久久久久久久久免费av| 能在线免费观看的黄片| 街头女战士在线观看网站| 国内精品一区二区在线观看| 国产在视频线在精品| 久久久久精品性色| 免费看美女性在线毛片视频| 搡女人真爽免费视频火全软件| 日本免费在线观看一区| 国产激情偷乱视频一区二区| 免费在线观看成人毛片| 亚洲欧美日韩卡通动漫| 亚洲av免费在线观看| 亚洲av中文av极速乱| 熟妇人妻久久中文字幕3abv| 亚洲精品一区蜜桃| 国产精品一区www在线观看| 亚洲精品久久午夜乱码| 一本—道久久a久久精品蜜桃钙片 精品乱码久久久久久99久播 | 97精品久久久久久久久久精品| 一级毛片 在线播放| 午夜福利在线在线| 三级男女做爰猛烈吃奶摸视频| 久久精品熟女亚洲av麻豆精品 | 日韩人妻高清精品专区| 少妇人妻一区二区三区视频| av国产免费在线观看| 免费av毛片视频| 少妇的逼好多水| 最近中文字幕高清免费大全6| 国产av不卡久久| 国产不卡一卡二| 日韩欧美 国产精品| 天天一区二区日本电影三级| 最近最新中文字幕大全电影3| 国产探花在线观看一区二区| 又爽又黄无遮挡网站| 亚洲综合精品二区| or卡值多少钱| 亚洲伊人久久精品综合| 在线观看av片永久免费下载| 97超碰精品成人国产| 乱码一卡2卡4卡精品| 日韩一区二区三区影片| 春色校园在线视频观看| 我要看日韩黄色一级片| 日韩欧美三级三区| 亚洲国产精品sss在线观看| 亚洲欧美精品自产自拍| 国产精品人妻久久久久久| 久久精品国产亚洲av天美| 国产一区二区亚洲精品在线观看| 亚洲怡红院男人天堂| 精品人妻视频免费看| 男的添女的下面高潮视频| 国内精品一区二区在线观看| 日日干狠狠操夜夜爽| av免费在线看不卡| 久久99精品国语久久久| 亚洲第一区二区三区不卡| 亚洲性久久影院| av专区在线播放| 丝袜喷水一区| 成年av动漫网址| 国产精品一二三区在线看| 中文乱码字字幕精品一区二区三区 | 美女大奶头视频| 亚洲精品aⅴ在线观看| .国产精品久久| 欧美激情久久久久久爽电影| 日韩欧美一区视频在线观看 | 五月玫瑰六月丁香| 亚洲欧美成人综合另类久久久| av在线观看视频网站免费| 国产成人精品久久久久久| 看十八女毛片水多多多| 91狼人影院| 久久久久久久久中文| 美女被艹到高潮喷水动态| av在线老鸭窝| 亚洲图色成人| 丝瓜视频免费看黄片| 一级av片app| 日本黄色片子视频| 韩国av在线不卡| 国产精品美女特级片免费视频播放器| 国语对白做爰xxxⅹ性视频网站| 91精品伊人久久大香线蕉| 啦啦啦中文免费视频观看日本| 青春草亚洲视频在线观看| 色综合站精品国产| 精品久久久久久久久av| 五月玫瑰六月丁香| 亚洲av免费在线观看| 日韩欧美三级三区| 亚洲精品色激情综合| 一级毛片 在线播放| 亚洲av男天堂| 亚洲av.av天堂| 亚洲av男天堂| 国产一区二区在线观看日韩| 婷婷色综合大香蕉| 久久久久精品久久久久真实原创| 久久国产乱子免费精品| 黄片无遮挡物在线观看| 国产黄频视频在线观看| 国产精品福利在线免费观看| 中文字幕av成人在线电影| 男女边摸边吃奶| 亚洲av国产av综合av卡| 亚洲精品日韩在线中文字幕| 日韩av不卡免费在线播放| 久久精品人妻少妇| 国产免费一级a男人的天堂| 日本-黄色视频高清免费观看| 永久网站在线| 身体一侧抽搐| 国产免费一级a男人的天堂| 中文天堂在线官网| 午夜日本视频在线| 高清av免费在线| 少妇熟女欧美另类| 夜夜看夜夜爽夜夜摸| 看非洲黑人一级黄片| 综合色av麻豆| 国产在视频线精品| 九九爱精品视频在线观看| 少妇熟女aⅴ在线视频| 国产真实伦视频高清在线观看| 免费播放大片免费观看视频在线观看| 国产精品一及| 国产av不卡久久| 18禁在线播放成人免费| 搡老妇女老女人老熟妇| 午夜福利在线观看吧| 亚洲av免费高清在线观看| 狂野欧美白嫩少妇大欣赏| 久久精品久久久久久久性| 亚洲精品456在线播放app| 久久久久久久国产电影| 久久精品国产鲁丝片午夜精品| 又黄又爽又刺激的免费视频.| 亚洲丝袜综合中文字幕| 国产白丝娇喘喷水9色精品| 久久久精品94久久精品| 亚洲国产精品国产精品| 神马国产精品三级电影在线观看| 六月丁香七月| 日日摸夜夜添夜夜添av毛片| 97超视频在线观看视频| 又爽又黄无遮挡网站| 纵有疾风起免费观看全集完整版 | 极品教师在线视频| 22中文网久久字幕| 亚洲欧美清纯卡通| 人妻制服诱惑在线中文字幕| a级毛片免费高清观看在线播放| 亚洲精品国产av蜜桃| 3wmmmm亚洲av在线观看| 禁无遮挡网站| kizo精华| 亚洲精品日韩av片在线观看| 一级毛片我不卡| 免费av观看视频| 亚洲av.av天堂| 久久精品久久久久久久性| 国内精品一区二区在线观看| 亚洲av成人av| 干丝袜人妻中文字幕| av天堂中文字幕网| 一级二级三级毛片免费看| 成年人午夜在线观看视频 | 欧美+日韩+精品| 国产成年人精品一区二区| 国产精品久久久久久久久免| 免费观看在线日韩| 一区二区三区四区激情视频| 亚洲图色成人| 中文欧美无线码| 欧美成人一区二区免费高清观看| av在线亚洲专区| 国产成人免费观看mmmm| 特大巨黑吊av在线直播| 国产精品一区二区三区四区免费观看| 国产精品一区二区三区四区久久| 精品酒店卫生间| 18+在线观看网站| 黑人高潮一二区| 国产精品嫩草影院av在线观看| 久久久欧美国产精品| 美女黄网站色视频| 精品一区二区三区视频在线| 亚洲最大成人中文| 欧美性猛交╳xxx乱大交人| 国产日韩欧美在线精品| 久久亚洲国产成人精品v| 男女视频在线观看网站免费| 最近手机中文字幕大全| 亚洲性久久影院| 亚洲av福利一区| 晚上一个人看的免费电影| 午夜福利高清视频| 性插视频无遮挡在线免费观看| 久久亚洲国产成人精品v| 欧美另类一区| 亚洲图色成人| 国产午夜福利久久久久久| 久久综合国产亚洲精品| 国产久久久一区二区三区| 婷婷色av中文字幕| 亚洲av二区三区四区| 嫩草影院精品99| 日韩欧美国产在线观看| 亚洲精品久久久久久婷婷小说| 成年人午夜在线观看视频 | 免费av观看视频| av国产免费在线观看| 一级毛片久久久久久久久女| 老师上课跳d突然被开到最大视频| 成年女人看的毛片在线观看| 免费观看性生交大片5| 久久久久免费精品人妻一区二区| 国产真实伦视频高清在线观看| 美女cb高潮喷水在线观看| 三级经典国产精品| 一二三四中文在线观看免费高清| 亚洲av中文av极速乱| 性插视频无遮挡在线免费观看| 国产伦理片在线播放av一区| 一级片'在线观看视频| 老女人水多毛片| 亚洲av成人精品一二三区| 免费黄色在线免费观看| 日本黄大片高清| 性插视频无遮挡在线免费观看| 久久精品国产亚洲av涩爱| 国产av不卡久久| 国产综合懂色| 亚洲怡红院男人天堂| 免费看日本二区| 汤姆久久久久久久影院中文字幕 | 中文字幕亚洲精品专区| av.在线天堂| 午夜福利视频精品| 91精品一卡2卡3卡4卡| 久久久久久久久久黄片| 免费黄网站久久成人精品| 国产精品福利在线免费观看| 亚洲精品日本国产第一区| 九九在线视频观看精品| 超碰av人人做人人爽久久| 国产成人一区二区在线| 久久精品久久精品一区二区三区| 国产熟女欧美一区二区| 国产精品一区www在线观看| 街头女战士在线观看网站| 18禁动态无遮挡网站| 精品国产三级普通话版| 十八禁国产超污无遮挡网站| 精品久久国产蜜桃| 十八禁网站网址无遮挡 | 纵有疾风起免费观看全集完整版 | 国产免费一级a男人的天堂| 韩国av在线不卡| 哪个播放器可以免费观看大片| 精品人妻一区二区三区麻豆| 一级a做视频免费观看| 搞女人的毛片| 18禁裸乳无遮挡免费网站照片| 我的老师免费观看完整版| 色视频www国产| 久久久精品94久久精品| 岛国毛片在线播放| 久久久色成人| 国产一区二区三区av在线| 精品久久久久久久久久久久久| 久久久国产一区二区| 亚洲性久久影院| 欧美xxxx黑人xx丫x性爽| 三级国产精品欧美在线观看| 久久精品久久久久久久性| 色综合亚洲欧美另类图片| 亚洲三级黄色毛片| 欧美一区二区亚洲| 国产男女超爽视频在线观看| 日韩 亚洲 欧美在线| 精华霜和精华液先用哪个| 免费黄频网站在线观看国产| 乱人视频在线观看| 国产精品一区二区在线观看99 | 成人亚洲欧美一区二区av| 在线 av 中文字幕| 自拍偷自拍亚洲精品老妇| 99久久人妻综合| 少妇的逼好多水| 欧美97在线视频| 天堂√8在线中文| 亚洲三级黄色毛片| 精品久久久久久久久av| 国产在线男女| 国产精品日韩av在线免费观看| 成人午夜精彩视频在线观看| 激情五月婷婷亚洲| 国产成人午夜福利电影在线观看| 淫秽高清视频在线观看| 日日摸夜夜添夜夜添av毛片| 免费大片18禁| 日本熟妇午夜| 国产av国产精品国产| 黄色一级大片看看| 男女视频在线观看网站免费| av天堂中文字幕网| 最近手机中文字幕大全| 国产成人精品久久久久久| 午夜精品在线福利| 中文天堂在线官网| 久久精品夜色国产| 国产三级在线视频| 又爽又黄无遮挡网站| 91午夜精品亚洲一区二区三区| 国产精品一区www在线观看| 国产乱人视频| 免费在线观看成人毛片| 国产午夜精品久久久久久一区二区三区| 天堂俺去俺来也www色官网 | 一区二区三区四区激情视频| 成年版毛片免费区| 欧美成人一区二区免费高清观看| 日本免费在线观看一区| 国产老妇伦熟女老妇高清| 日韩av不卡免费在线播放| 韩国av在线不卡| 亚洲欧美日韩无卡精品| 极品教师在线视频| 搡女人真爽免费视频火全软件| 精品亚洲乱码少妇综合久久| 亚洲精品乱久久久久久| 一级毛片aaaaaa免费看小| 久久精品综合一区二区三区| 亚洲精品一二三| 校园人妻丝袜中文字幕| 看十八女毛片水多多多| 亚洲综合精品二区| 两个人的视频大全免费| 久久精品久久久久久久性| 国产精品国产三级国产av玫瑰| 伦精品一区二区三区| 大香蕉97超碰在线| 免费观看a级毛片全部| 精品国内亚洲2022精品成人| 久久精品久久精品一区二区三区| 边亲边吃奶的免费视频| 免费黄网站久久成人精品| 一级毛片电影观看| 最近中文字幕2019免费版| 99热6这里只有精品| 亚洲av成人精品一二三区| 国产又色又爽无遮挡免| 插阴视频在线观看视频| av播播在线观看一区| 国产精品麻豆人妻色哟哟久久 | av.在线天堂| 一级av片app| 九色成人免费人妻av| 女人久久www免费人成看片| 三级毛片av免费| 美女国产视频在线观看| 高清视频免费观看一区二区 | av播播在线观看一区| 久久久久久久亚洲中文字幕| 久久精品久久精品一区二区三区| ponron亚洲| 欧美成人午夜免费资源| 91久久精品国产一区二区三区| 99视频精品全部免费 在线| 国产69精品久久久久777片| 久久久久久久久久黄片| 国内精品一区二区在线观看| 国产精品美女特级片免费视频播放器| 色综合亚洲欧美另类图片| 欧美+日韩+精品| 亚洲国产精品成人久久小说| 亚洲怡红院男人天堂| 尾随美女入室| 亚洲av免费高清在线观看| 久久99蜜桃精品久久| 99久久人妻综合| 又粗又硬又长又爽又黄的视频| 色综合亚洲欧美另类图片| 日本wwww免费看| 精品久久久久久久久久久久久| 有码 亚洲区|