Question

By the time Jack returned home from England, his son __________from college.

A. graduated
B. has graduated
C. had been graduating
D. had graduated

Answer 1

答案D
本题考查动词时态。句意为“当杰克从英国返回家时，他的儿子已经大学毕业了。”by the time到…时候为止，一般与完成时连用。选D。