prep1-3 句子结构

verylotus

同问，since后面可以接过去完成时的吧。。C错会不会是因为since的主句和从句不能时态相同啊？

zouchengru

顶上来，c错的原始究竟是加不加in，还是SINCE后面的时态不对

jaze

好像想通了

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.



在这个句子中

Less than 35 years 其实是做状语修饰 the release 的，这也符合上面例子的解释，即无 in 表示任何一时间点的事件，一次性动作。
有 in 表示时间段。重复性动作。release 是一次性动作而非重复性动作，故即便是其他部分不变，改成 in less than 也是不正确的。
In 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.

通过此点，可以排除 B,C
另外全句的实际状语是　after the release of African honeybees outside Sao Paulo, Brazil,　而非 Less than 35 years after the release of African honeybees outside Sao Paulo, Brazil,
   

仔细比较他们的差异
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.

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.

-- by 会员 songlovegt (2009/2/12 4:40:00)

好像不是这样的吧，
Less than 35 years 其实是做状语修饰 the release 的    这怎么可能？   the release 是after的宾语， 这里应该是  介宾短语 == 形容词来修饰 35 years的吧。 而且 less  than  的逻辑主语是  their descendants ， less than  在句中作状语修饰的是  migrate  这个动作

整句话简要意思就是    在它们释放还不到  35年就  迁徙到了。。。。。

kevinjpcn

被这道题考到了，开始做的时候，觉得所有选项都不对，最后无奈只有选择B
。因为没有见过less than的这种做状语用法。
太奇怪了，语法点太多了。GMAT的语法是参考哪本书出题的啊。

kakadinho

这道题C选项不对的原因其实很简单：

对于过去完成时，在句中应该有一个明确的specific time of past可以对应，才能表达“过去的过去”。

而划线部分的时间状语（先不管正确选项是啥），给主句的had migrated提供了那个specific time of past; 但是如果在划线部分又出现一个had been released, 这个动作对应的specific time of past是没有在句中出现的，所以划线部分不能再用过去完成时了。当然，C还有一个小错误，就是the应该去掉。

而至于A为什么不能用“in”，我觉得原因是这样的：

“（less than 35 years） after X”  只表达了一个“在X之后某个小于35年的时间点” ； “In less than 35 years after X" 表示 ”在X之后的不到35年间“。 一个是过去的时间点，一个是过去的时间段，这个时候如何选择就要看谓语动词的意思了:

而migrate用了过去完成时had migrated，表示过去已经完成了，而且migrate是一个动作（虽然所有蜜蜂不可能完全同时一次性迁移，但迁移本身就是一个动作），动作的过去完成时 就是在某个过去的时间点之前该动作全部完成了；(如果有人纠结在"即使是一个动作，但migrate不是应该是35年间不断发生的么”，那好，这样是否应该用had been migrating呢)

而migrate不是一个状态，状态的过去完成时 才可能是”在过去某个时间段之间都已经是某个状态了“。

所以：had migrated less than 35 years after X  = 在X之后不到35年的某个时间点之前，所有descendants都迁移完了；

综上，总结一下：
1. 每个在句中出现的过去完成时，都应该有一个specific time of past与之形成时间的对应；
2. 关于过去完成时对应的specific time of past是时间段，还是时间点，要看谓语动词的情况是：1）时间点：一次性动作；2）时间段：持续性或重复性动作，或者状态
可以再举个例子：
I had married 2 years before the Second World War. 我在二战前2年就已经结过婚了。
I had been single in 2 years before the Second World War. 我在二战之前的2年内已经是单身了。

zwhjzwhj

这道题真是晕忽忽，而且题号还不好搜，最怕这种单数的题号了。搜一个prep 3，出来19页搜索结果，只要带3的都有。什么时候CD可以按内容搜索而不单单按标题搜索就好了。。。

cherrywyr

关于有没有in的说法，以下是Ron的解释
Why the option A uses "Less than 35 years after..." rather than "In less than 35 years after..." ?


i'm with you on this one; i'd likewise prefer a wording such as 'in less than 35 years after...', because, in my opinion, it better conveys the idea that the migrations took place continuously over the 35-year period. just plain 'less than' seemed to me, and possibly to you as well, to suggest that the migrations might have occurred all at once.

in any case, though, you've got to remember that correctness trumps clarity (and definitely trumps concision as well). therefore, differences in wording, such as this one, are trifling in comparison to actual errors in usage, grammar, diction, or idiom. i think both of us will agree that there is no idiom error in the wording chosen here; it's just a somewhat awkward wording (a situation by no means uncommon on the real test).