We'd better take umbrellas—I'm sure it when we arrive in London; it's always wet there at this time of year．
A. will rain
B. is raining
C. will be raining
D. would rain
网友回答
A. will rain
B. is raining
(答案→)C. will be raining
D. would rain
解析：考查将来进行时。A一般将来时；B现在进行时；C将来进行时；D过去将来时。时态题的解题关键是看时间状语或动词的时态。根据时间状语“when we arrive in London（当我们到达伦敦时）”可知是将来某一时刻，将来某一时刻发生的动作要用将来进行时，故选C。