NN解惑：大全325

atc

Geologists believe that the Bering land bridge, over which human beings are thought to have first entered the Americans, disappeared about 14,000 years ago when massive glaciers melted and caused the sea level to rise several hundred feet worldwide.

(A) are thought to have first entered

(B) were thought first to enter

(C) were thought at first to enter

(D) are thought of as first entering

(E) were thought to first enter

答案：（A）

疑惑1）为什么用现在完成时态

        2）WHO caused the sea level to rise several hundred feet worldwide，感觉massive glaciers似乎不对，因该是massive glaciers melted 这件事情？

allln123123

毕竟用were更加不妥,还是要用are

atc

用排除法可以得到选A啦，但是那2个问题还没有解决呀？

prayer

你的问题我一个也解决不了，因为我选了E.

我是感觉完成时不太对，另一个are的更不对。human beings通过大陆桥进入美洲应该是过去一点发生的，而不是延续到现在，现在大陆桥都消失了。

不过to do有表示将来的意思（prep里解释说的），没有一个答案好啊

吴羽若

我也选E的，总觉得完成时没必要，看样子还在争议中啊。

Hattielin87

confused中。。。。。

特强薄荷

NN快来回答啊