By the time he arrives in Beijing, we here for two days.
A. will have stayed
B. will be staying
C. have been staying
D. have stayed
网友回答
(答案→)A. will have stayed
B. will be staying
C. have been staying
D. have stayed
解析：考查时态：句意：在他到北京的时候为止，我们已经呆在这儿两天了。说明我们在这儿待两天是在他到这儿之前，用过去完成时。还有介词by，是和相应的完成式连用的，by接过去时间，用过去完成时，by接将来时间，用将来完成时。选A。