Unit3WeshouldobeytherulesLesson15情态动词should的用法1.shoulddo“表现在，可将来”shouldhavedone“表过去”应该Weshouldlearnaboutthecomputerandmakefulluseofit.我们应该了解计算机并加以充分利用。Youshouldlistentothedoctor’sadvice.你应当听大夫的话。Ishouldhavefinishedmywork.我应该做完我的工作。（实际上还没有做完）mustn’t,shouldn’thadbetternotTheyshouldn’tleftsosoon.表禁止Youshoulddowhatyourparentstellyou.Ioftenseelightsinthatemptyhouse.DoyouthinkIshouldreportittothepolice?should,musthaveto表义务(应该)有时态变化---I’lltellMaryabouthernewjobtomorrow.---Youshouldhavetoldherlastweek.表示与过去事实的相反,意为“本应该……”2.在Itis/wasrightthat...类句型的that从句中，以虚拟语气表示“应该如此”或“不合理”、“难以置信”、“不该如此”等意思（事实并非如愿）。例如：Itis/wasnowonderthatheshouldhavesucceeded.(表过去)难怪他会成功。Itis/wasapitythatheshouldhavefailed.（表过去）真可惜他失败了。Itisnotrightthatoneshouldspeakillofothers.(表现在及未来)说别人的坏话是不对的。Itisstrangethatyoushouldsayso.(表现在)你这样说话真奇怪呀！这一句型还可用以下这些词来代替right等词。natural,necessary,strange,important,advisable,better,desirable(合意的),essential,good,proper,well,urgent,wrong,funny,pitiful,athousandpities,regrettable(令人惋惜的)，toberegretted（令人惋惜的）,surprising(令人吃惊的)类似句型还有：（以下句中should意为“竟然，居然会”）IamsorrythatIshouldhavespokensorudely.(表过去)我很抱歉我竟然说话那么粗鲁。Whatareyou(Iamsuprised)thatyoushouldhavesoinsultedourteacher?(表过去)你是谁竟然对我们老师如此无礼？3.表明显的结果或合理的推论，且所期待的事几乎是事实。不是虚拟语气。例如：Marytookdancingdessonsforyears;sheshouldbeanexcellentdancer.玛丽学了几年的舞蹈，她该是位很优秀的舞蹈家。Itisthreeo’clock;thefootballgameshouldbeginsoon.已是3点钟了，足球比赛开始了。4.在疑问句中表示惊讶、不合理、难以置信或不应说的事。例如：WhyshouldIgo?我干嘛要去？（不满）Whyshouldhepublishsuchabook?为何他竟会出版这种书？Whyshouldyoubesorryaboutthenews?你为何对这消息感到难过？Shouldhedosuchathing?他会做这种事吗？...
