在各类考试和历届高考试题中it+be+time+conj句型以不同的形式出现,往往使考生顾此失彼,一头雾水,原因在于没有搞清楚各个句型的特点及实质,现结合历届高考题分别予以探究,以便考生在应用中有的放矢.
(一)It is (has been)+时间段+since+clause
此句型的要点 (1)在于since前后句子的时态.since前的时态为is或has been, 后的时态为一般过去时
Eg: It is(has been) ten years since I joined the army
译为: 我参军已经十年了.
要点(2) since后的动词若为延续性或状态性动词,应译为否定或相反,若为短暂性动词按字面意思翻译.
Eg:1It is(has been) ten years since I was a teacher
=It is(has been) ten years since I left the army
译为: 我复员十年了.
It is ten years since I smoked
=It is ten years since I stopped smoking
译为: 我戒烟十年了.
练习: 1－What was the party like？
－Wonderful. It’s years____ I enjoyed myself so much
A: after B:before C:when D:since
思考: 该句怎么翻译？
2I live in Beijing now, that’s to say, it’s ten years since I ____Beijing.
A:lived in B:left for C:left D:was in 3I’m a teacher now, that’s to say, it is ten years since I___ a teacher.
A: have been B: was C:became D:turned
Key.1D 2B 3C
（二）It will be(was)+时间段+before+一般现在时态的clause(一般过去时)
Note: 此句型和句型(一)的共性都加时间段,差异在于前后的时态和翻译
Eg: 1It will be ten years before I return home.
译为:要过十年我才能回家.
2It was ten years before he found his lost boy.
译为:过了十年他才练习:找到了他失踪的儿子.
练习:1It is reported that it may be two or three months_____it is possible to test this medicine on animals
A:since B:after C:before D:when
2－How long do you think it will be ______ China sends a manned spaceship to the moon？
－Perhaps two or three years (2006.福建)
A:when B:until C:that D:before
3How long do you think ____ the computer company brings out a new product？(2005.上海)
A: it will be before B:will it be until
C:will it be when D: it will be that
Key:1C 2D 3A
（三）It will be(was) +时间点+when+一般现在时态的clause(一般过去时)
Note: 和句型(二)比较:前后时态一致,但此句型中为时间点而非时间段
Eg: 1 It will be midnight when I return home.
译为: 我回到家的时间将是午夜.
2It was noon when the accident happened
译为: 事故发生时已是正午.
练习:1___ was 1979 ____ I graduated from university (1997.上海)
A:That; that B:It; that C:That; when D:It; when
2It was breakfast _____ our teacher punished me (2004.北京)
A:when B: until C:since D: before
Key: 1D 2A
(四)It is(was)+时间点+that的强调句型
Note:与句型（三）比较时间前通常有介词且去掉it is(was)……that之后句子仍然成立。
Eg:①It was in the morning that I was robbed in the street.
=It was this morning that I was robbed in the street.
②It was at 7:00 that I met Tom this morning.
=It was 7:00 when I met Tom this morning.
综合操练：
① He was told that it would be at least three more months ____ he could recover and return to work. ( 2007.江西)
A: when B: before C:since D:that
② The field research will take Jone and Paul about five months; it will be a long time ___ we meet them again. (2007.安徽)
A: after B:before C:since D:when
③ It was some time ___ we realized the truth (2005.山东)
A: when B: until C: since D: before
④ It is almost five years ____ we saw each other last time (2005.北京)
A:before B:since C:after D:when
⑤ It was about 600 years ago ____ the first clock with a face and an hour hand was made (NMET.1997)
