关于OG 13,SC, 76题，我不理解这个现在完成时态。

quoxo

Combining enormous physical strength with higher intelligence, the Neanderthals appear as equipped for facing any obstacle the environment could put in their path, but their relatively sudden disappearance during the Paleolithic era indicates that an inability to adapt to some environmental change led to their extinction.

(A) appear as equipped for facing any obstacle the environment could put in their path,
(B) appear to have been equipped to face any obstacle the environment could put in their path,
(C) appear as equipped to face any obstacle the environment could put in their paths,
(D) appeared as equipped to face any obstacle the environment could put in their paths,
(E) appeared to have been equipped for facing any obstacle the environment could put in their path,

这道题有好几种方法都可以选到正确答案，比如as...as,paths，equip to，或者appear的时态。但是，这些跟OG最主要的解释都不一样，而且OG的解释我很不理解。
OG：Because Neanderthals "disappeared," the verb describing their apparent abilities cannot be present tense, so  as equipped must be changed to have been equipped.我的疑惑是:为什么要用“have been equipped"?

sisichen666

这里不是现在完成时，给你来个native的解答：
this isn't a present perfect construction, because it's actually an infinitive.
i.e., it's not "they have been equipped"; it's "they appear TO HAVE been equipped".

in any case, you should probably just memorize this construction as a one-off idiomatic structure. if you say "they seemed/appeared to...", then, no matter how remote the event is (in time), you use this construction.

for instance:
it seems that the students cheated on the exam
(normal past tense in this construction)
but...
the students seem to have cheated on the exam
(not here)

i don't really have a good explanation for this, other than "i'm a writer with a firm command of formal english, and i know that it is so" and "you should just think of it as an idiom". sorry i can't do better than that.

in any case, though, you DO have to use an infinitive after "appear" or "seem" in this sort of construction. and if you think about it, this is as past-tense as an infinitive can get. so that's why you have to use it.

quoxo

非常感谢，sisichen666.

kaye523

醍醐灌顶！谢谢！

eriiiii

sisichen666 发表于 2012-11-7 22:18
这里不是现在完成时，给你来个native的解答：this isn't a present perfect construction, because it's ac ...

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