(1/2)____that the train is gone,it is useless to wait. A Seen B see

(1/2)____that the train is gone,it is useless to wait. A Seen B see
(1/2)____that the train is gone,it is useless to wait. A Seen B see

(1/2)____that the train is gone,it is useless to wait. A Seen B see
A Seen 表示 完成时态

see

A

有其他答案吗？

应该填：B.项 see

when

建议选同为分词的seen，本来应该现在分词表原因构成独立主格。 原题应该是21.____ that the train is gone, it is useless to wait.A. Seen B. Seeing C. Having seen D. to have seen

B因为选A的话结构不完整，应该是having seen，A的话有被动含义，说不通。B是指看到火车离开，而且远B视之为感官动词，有这种用法。

我认为这道题选A 这句话应该是这样的：.It is useless to wait that seeing the train is gone. /it is useless to wait seen that the train is gone. seen在这里表示被动。