Mr Smith a book about China last year but I don’t know whether he has finished it.
A. has written
B. wrote
C. had written
D. was writing
网友回答
A. has written
B. wrote
C. had written
(答案→)D. was writing
解析：考查时态。句意：去年史密斯先生一直在写一本关于中国的书，但是我不知道他是否已经完成了。结合语境可知前文描述的是在过去一直在进行的动作，故用过去进行时态，选D。