Question

—Have you seen your friend off ?
—Yes. I watched the train leaving the station        it disappeared from sight.

A．unless

B．as if

C．so that

D．until

Answer 1

D

試題分析：考查詞和詞組意思，unless意思“除非”， as if意思“好像”，so that意思“以至于”，until意思“直到……”，句子意思“我看卓火車離開車站直到從我的眼前消失”，所以選D
點評：固定詞組see off意思“送行”，watch sb do sth意思“看到某人做什么”，watch sb doing sth意思“看到某人正在做某事”，強調動作正在發生。