问题
选择题
By the time you arrive in Liverpool, we ___________ in France for two weeks.
A．shall stay
B．have stayed
C．will have stayed
D．have been staying
答案
答案：C
考察时态。句意：当你到达利物浦时，我们已经在法国两个星期了。可知下文描述的是在将来某个时间点前完成的动作，故用将来完成时态，选C。