Question

Don’t disturb me. I_______ letters all morning and have written ten so far.

1. A.
   have written
2. B.
   am writing
3. C.
   was writing
4. D.
   have been writing

Answer 1

D
试题分析：句意：不要打扰我，我整个早晨一直在写信，到目前为止已经写了十封信。因为有all morning强调动作一直在进行，故用现在完成进行时，故选D。
考点：考查动词时态的用法。
点评：本题难度适中。动词时态的考查与一定的语境结合一起增加了试题的难度，有的考生时态的用法背的很熟，但在不同的语境下，就做不对了，提醒考生一定要会分析理解语境。这里考生误选C。
即学即练：Experiments of this kind        in both the U.S. and Europe well before the Second World War.
A. have conducted    B. have been conducted
C. had conducted    D. had been conducted
解析：D。句意：就在二战爆发前，美国和欧洲都进行过这种实验。”首先考虑语态，主语experiment与conduct构成动宾关系，谓语使用被动形式。题干中出现the second war是过去的时间点，before the second war是过去的过去，因此使用过去完成时。选D。