A.returned
B.had returned
C.have been returned
D.have returned
562.By the time you arrive in London,we _______ in Europe for two weeks.
A.shall stay
B.have stayed
C.will have stayed
D.have been staying
561.答案是C;此题强调对现在的影响。
562.答案是C;by the time+从句表示将来时间时,主句用将来完成时。



