3. 根据上、下文来判定

　　I met Wang Tao in the street yesterday. We hadn't seen each other since he went to Beijing.昨天我在街上遇到了王涛。自从他去了北京我们一直还没有见过彼此。

　　四. 过去完成时与一般过去时的区别

　　虽然这两种时态都表示过去发生的动作或存在的状态，但在使用时应注意以下两点：

　　1. 时间状语不同，过去完成时在时间上强调“过去的过去”;而一般过去时只强调过去某一特定的时间。试比较：

　　They had arrived at the station by ten yesterday.到昨天十点为止，他们已经到达了车站。

　　They arrived at the station at ten yesterday.他们在昨天十点的时候到达车站。

　　2. 在没有明确的过去时间状语作标志时，谓语动词动作发生的时间先后须依据上下文来判断，先发生的用过去完成时，后发生的则用一般过去时。例如：

　　She was very happy. Her whole family were pleased with her, too. She had just won the first in the composition competition. 她很高兴。她的全家对她也很满意。她刚刚在作文比赛中得了第一。

　　五、练习及答案

　　【典型考例】John and I____ friends for eight years. We first got to know each other at a Christmas party. But we_____ each other a couple of times before that. A. had been; have met B. have been; have metC. had been; had met D. have been; had met

　　【析】正确答案是D。句意是：约翰和我是8年的朋友了。我们第一次是在一词圣诞聚会上互相认识的。但是这那之前我们就已经碰过好几次面了。第一句指从过去延续到现在的状况，应使用现在完成时“have(has)+过去分词”，第二句表示在我们成为朋友之前过去的动作，即“过去的过去”，应使用过去完成时“had+过去分词”，因此本题的正确答案为D。

　　一、

　　1. We _____________ (paint) the house before we ______________ (move) in.

　　2. That rich old man _____________ (make) a will before he _____________ (die).

　　3. They _____________ (study) the map of the country before they ________ (leave).

　　4. The robbers _____________ (run )away before the policemen _______ (arrive).

　　5. I __________ (turn) off all the lights before I ____________ (go) to bed.

　　6. Paul __________ (go) out with Jane after he __________ (make) a phone call.

　　7. Tom __________ (say) he ___________ (read) the book twice.

　　8. Our plan ____________ (fail ) because we _____________ (make) a bad mistake.

　　9. She told me she _________________(be) to Chongqing three times.

　　10.He said he _____________already_________(give) the book to the teacher.

　　11.When I ______________(get) at the station, the train ____________________(leave).

　　12.We _______________(learn) about 4000 English words by the end of last term.

　　13. I waited until he _______________(finish) his homework.

　　14. We were surprised at what she ________already ______(do)