问题补充:
If you reading that book, take it back to the library.
A. have finished
B. will finish
C. finished
D. are finishing
答案:
(答案→)A. have finished
B. will finish
C. finished
D. are finishing
解析:句意:如果你已经读完了那本书,把它放回到图书馆。根据句意可知,如果你已经读完,这里强调的是结果“完成”。故用现在完成时。在条件状语从句中,用现在完成时代替将来完成时。故选A。