GWD题A、B不会比，求助！

azhongzhong

（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
我选B，为何A比B好？

frank73110

1、since是现在时，注意后面是had migrated
2、since releasing要求逻辑主语和句子主语一样，就变成了their descendants了. 而不是African honeybees。

azhongzhong

这两个我都不懂呢,1.since 是现在时的标志对吧。而不是since是现在时吧。
                             2、since releasing要求逻辑主语和句子主语一样，就变成了their descendants了，their descendants since releasing African honeybees 有什么不妥吗？难道是African honeybees since releasing African honeybees？