The train ______ late, we all had to wait.
(A) been
(B) was
(C) being
(D) is
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
认同要用 was 的话，这句应该是 The train was late so we all had to wait.