2、This has proved difficult because he own over a hundred books which covered every inch of floor space at the moment. (双重复合句)
【Composition】 作文
1、when
2、not only....but.....as well (会放在there be 后面)
3、since: 因为, 由于(=because)
【Key structures】 关键句型
现在完成时 have done
现在完成进行时 have been doing
I have read the book书已看完
I have been reading the book还没看完, 还要继续
I have read 'Oliver Twist' five times.
与段时间连用可以用现在完成时, 也可以用现在完成进行时, 但跟次数连用的, 一定只能用完成时, 不能用现在完成进行时
He has rung me up five times since 12 o’clock.
【语法精髓】P9 用所给动词正确时态填空
1、You should go to bed.you _____ (watch) TV for 5 hours.
2、I _____ (write) letters since breakfast.
3、I _____ (write) 3 letters since breakfast.
4、Sorry, but Mr.Smith _____ (leave) for Beijing.
5、I _____ (look) for him everywhere, where can he be?
1、have been watching/have watched
2、having been writing
3、have written
4、has left
leave是瞬间动词
1、和现在完成进行时连用的, 一定不能是次数