be known to....求教

juan

are now known to have had brains..... to have done表达动作发生在known前。没错。可难道have brains这个动作在known之后就不发生了吗？我觉得have brains....是个客观事实呀。。晕了......

liu_9000

同意楼上。C的were说明是过去一样大。现在可能收缩或者化石了呢。

A的have had brains强调过去有brains不知道是什么意思。have表示一种状态。这个状态持续到某个时间没有了。不可理解。不知道这是什么地方的题？

groundkeeper

考古题,another similar question:

The line of descent of apes and human is believed by most paleontologists that it split into several branches some time between 20 million and 5 million years ago.

(B) to have split

(C) to split

(D) that they were split

(E) to be split

juan

我觉得这题和上面那道不一样。

这题该选B. 因为后面的sometime between 20 million and 5 million years ago表明split into..是发生在过去。而且split这个动作完全是可能当时发生完就结束了的，不会再延续到现在,总不可能到现在还在split吧？所以当然应该用is believed to have split。

而前面那道题，穴居人have brains....是过去,现在,将来都存在的事实呀.怎么能用to have had brains呢?

唐三彩

完成时强调的是已经发生的事情，并不表示以后不发生。就好比: I have know the fact——表示我已经知道事实了（以后也一直是知道的）。。。。。

所以用完成时来强调“已经“这个概念是可以的。。。当然如果选项里面没有完成时，也可以使用现在时的。。。

bon

11. The Neanderthals, once considered dull-witted brutes, are now known to have had brains fully as large as our own.

(B) as having brains that are

(C) to have brains that were

(D) that their brains were

(E) that they had brains that were

c的were表示过去是，现在不是，

作为阐述一个事实，我认为这样的表达错误，用are 合适

另外

The line of descent of apes and human is believed by most paleontologists that it split into several branches some time between 20 million and 5 million years ago.

(B) to have split

(C) to split

(D) that they were split

(E) to be split这道题是选c吗？

juan

The line of descent of apes and human is believed by most paleontologists that it split into several branches some time between 20 million and 5 million years ago.

(B) to have split

(C) to split

(D) that they were split

(E) to be split

这题选B吧？

LES

偶选B。

groundkeeper

以下是引用juan在2004-6-28 14:12:00的发言：

The line of descent of apes and human is believed by most paleontologists that it split into several branches some time between 20 million and 5 million years ago.

(B) to have split

(C) to split

(D) that they were split

(E) to be split

这题选B吧？

the given answer is B,