19.
That village tended to be impoverished settlements __________off from
civilization by the high mountain.
(A)cutting
(B)to cut
(C) cut
(D) to be cut
阿摩线上测验:
http://www.yamol.tw/exam-TOEIC+%E6%96%87%E6%B3%95%E7%B7%B4%E7%BF%92%28650
800%297926-7926.htm#ixzz4MqYkgwhT
疑问：为什么是C
是被动态故选过去分词 cut off?
能否有更浅显或详细的说明. 感恩~