请教GMAT中since的用法！附题！

tim_zyb

我想知道since的主句可以是过去完成时吗？since从句可以接过去完成时吗？如果可以应该怎么用呢？

副一道题 方便解释

3.    (24557-!-item-!-188;#058&001027)

 

Less than 35 years after the release of African honeybees outside Sao Paulo, Brazil, their descendants, popularly known as killer bees, had migrated as far north as southern Texas.

 

(A) Less than 35 years after the release of African honeybees outside Sao Paulo, Brazil,

(B) In less than 35 years since releasing African honeybees outside Sao Paulo, Brazil,

(C) In less than the 35 years since African honeybees had been released outside Sao Paulo, Brazil,

(D) It took less than 35 years from the release of African honeybees outside Sao Paulo, Brazil, when

(E) It took less than the 35 years after the time that African honeybees were released outside Sao Paulo, Brazil, and then

C怎么错了呢？答案是A

[此贴子已经被作者于2008-7-1 22:25:11编辑过]