4、一些重要的時間狀語

1)、during the last fifty years最近50年間 (注意last 前面的the)

E：The change that have taken place in air travel during the last sixty years would have seemed completely impossible to even the most brilliant scientists at the turn of the 19th century.

2)、by:不遲于，在……之前，到……為止

表示動作在某一時刻之前完成，常用于完成時句子。

E1、By the time the doctor arrived the patient had died.(過去完成時)

E2、By 2005 the population will have risen to over 15 billion.(將來完成時)

3)、till/until 直到……

注意和BY的區別，它們表示“某動作完成的終止點”。

E: She finished her experiment by 11o’clock.

She did her experiment till/until 11 o’colck.

4)、so far 到現在為止

so far this morning 今天上午到現在為止

5、練習：

1)、By the time you arrive in London,we_____(stay)in Europe for two weeks.

2)、The first two factors must be equal for all who are being compared,if any comparison in terms of intelligence____(make)

3)、While you were in London that year,the London Bridge_____(repair).

4)、John is’t a diligent student,for it is the third time he____(be)late,isn’t it?

5)、John always works in his lab and makes a lot of experiments,He___(make)experiments all afternoon and____(not finish)yet.

6)、It___(be)very cold lately,but it’s beginning to get a bit warmer.