Wait a moment, please. When I writing the letter, I will go shopping with you.
A. will have finished
B. have finished
C. will finish
D. finished
网友回答
A. will have finished
(答案→)B. have finished
C. will finish
D. finished
解析：句意：请等会，当我写完这封信的时候，我会和你去购物。这里主句是一般将来时，从句不能用一般将来时，可以用一般现在时或现在完成时，所以选B。