问题补充：
---When and visit our exhibition next month ?
-- -When , I will let you know .
A. will he come ; he will come
B. will he come ; he comes
C. does he come ; he will come
D. does he come ; he comes
答案：
A. will he come ; he will come
(答案→)B. will he come ; he comes
C. does he come ; he will come
D. does he come ; he comes
解析：第一句中的时间状语next month确定了这句的一般将来时的时态，然而第二句是由when引导的时间状语从句，在时间状语从句中只能用一般现在时表示的是一般将来时。
