When he arrived at the bus stop, the bus for 20 minutes.A. has left B. had left C. has ——青夏教育精英家教网—

1. When he arrived at the bus stop, the bus ________ for 20 minutes.

A. has left B. had left C. has been away D. had been away

2、句子中有一些特征词。

Already ever never just yet since…. For…..

He _____already _____ (see) the film.

I _______ never ______ (learn)English .

_______ you ______ (finish) your homework yet?

The meeting ______ (begin) for two hours.

动词按其动作发生的方式、发生过程的长短可分为延续性动词与非延续性动词。

一.延续性动词表示能够延续的动作,如：learn, work, stand, lie, know, walk, keep, have, wait, watch, sing, read, sleep, live, stay等。延续性动词可以与表示时间段的状语连用。

表示时间段的短语有:for+一段时间,for 2 years; since从句,since he came here; since+时间点名词,since last year, since 5 days ago; how long; for a long time等。

例:He has lived here for 6 years. You can keep the book for 5 days. I stayed there for 2 weeks last year. How long did you stay there last year?

二.非延续性动词也称终止性动词、瞬间动词,表示不能延续的动作,这种动作发生后立即结束。如:open, die, close, begin, finish, come, go, move, borrow, lend, buy等。

非延续性动词在肯定句中与表示时间点的状语连用，如：two years ago; at 5 o'clock;

例:He died 5 years ago.

否定的终止性动词可以与表示时间段的时间状语连用。例:I haven't left here for 3 years. I haven't heard from him for 3 weeks.

三.延续性动词与非延续性动词之间的转换：leave --- be away, borrow --- keep, buy --- have, begin/start --- be on, die --- be dead, finish --- be over, join --- be in+组织机构, be a member of+组织机构, open sth --- keep sth open, fall ill --- be ill, get up---be up, catch a cold --- have a cold, come here --- be here, go there --- be there, become --- be, come back --- be back, fall asleep --- be asleep, get to/ arrive/reach --- be (in), leave --- be away from, get to know --- know, go (get) out →be out， put on→ wear；catch a cold →have a cold等。例:The old man died 4 years ago. ----The old man has been dead for 4 years. ---- It is 4 years since the old man died. ----Four years has passed since the old man died. He joined the Party 2 years ago. -----He has been in the Party for 2 years. I bought the book 5 days ago. ---- I have had the book for 5 days.

补充练习：

1、句子中没有明确的时间。

He _____ (die) last year

He _____ (die) next week.

He _____ (die) now.

He _____ (die)

注：对直线不存在斜率的情形，可不做证明.