Shirley _______ a book about china last year but I don’t know whether she has finish it

D . was writing
时间是last year，用过去时，排除A,C
而根据题意“I don’t know whether she has finished it(我不知道她是否已经写完)”，所以用进行时was writing，表示动作的持续,符合题意。而wrote表示“（过去）已写完”，与题意不符合。

B . wrote 根据last year 用过去时

b