第20练 含有for和since的现在完成时 -2022年【暑假分层作业】八年级英语（人教版）

第20练 含有for和since的现在完成时 since和for是现在完成时当中常见的标志词。since“自从……”，for“持续了……”。since用来说明动作的开始时间，for用来说明动作延续的时间长度 考点1 since和for是现在完成时的重要标志 考点2 since和for的用法 （1）since的用法 since+过去的时间点。如：年、月、日、几点等 ☞since 1990 自从1990年起 ☞since 5 o’clock 自从五点起 since+ 时间段+ ago ☞since 3 months ago 自从三个月以前 since+ 一般过去时的从句 ☞since you left home 自从你离开家以后 （2）since的一个固定句式“It is＋时间段＋since＋一般过去时的从句”。 It is five years since I came here. 我来这儿5年了。 （3）for的用法：for＋时间段 （4）在现在完成时当中，若对since和for引导的时间状语进行提问，都可以用how long来提问。 （5）since和for的句式转换： since＋时间段＋ago＝for＋时间段 They haven't changed since twenty years ago. ＝They haven't changed for twenty years. 他们已经二十年没有改变了。 考点3 延续性动词、短暂性动词与since, for 延续性动词表示能够延续的动作。短暂性动词表示不能延续的动作，这种动作发生后立即结束。 (1) 若现在完成时的句子中含表示时间段的时间状语(如含since/for引导的时间状语)，则谓语只能使用延续性动词。 (2) 短暂性动词可以转化为延续性动词 ①直接换成延续性动词　 buy买→have有　borrow借→keep保留　put on穿上→wear穿着come/go/become来/去/变成→be在/是 ②转换成be＋名词 join the army参军→be a soldier当兵 join the Party 入党→be a Party member成为一名党员 go to school去上学→be a student成为一名学生 ③转换成be＋形容词/副词 die死亡→be dead死了 finish结束→be over结束 begin开始→be on 在上映/已开始 leave离开→be away远离的 fall asleep入睡→be asleep睡着的 close关闭→be closed关着的 ④转换成be＋介词短语 go to school去上学→be in school在上学 join the army参军→be in the army在军队中 一、单项选择 1．—Jenny, your new soft toy looks very beautiful. —Oh, it is not new. I ________ it for three months. A．have had B．have bought C．bought 2．Li Hua ________ the book for one week. A．bought B．has bought C．kept D．has kept 3．I’ve worked as a teacher in this school ________ 10 years ________ 2011. A．since; for B．for; since C．for; for D．since; since 4．My mother ________ a good example for me since I ________ a child. A．was; was B．will be; is C．has been; was D．was; has been 5．—How long have you ________ the computer, Jack? —For three month. My parents bought it for my 13th birthday. A．borrowed B．bought C．caught D．had 6．—How many friends has Frank made ________ he came to the new school? —At least ten, I think. A．ever since B．as soon as C．while D．until 7．Zhao Lan ________ alre