7.I’ll go camping with you,if I _____ free tomorrow.

问题描述:

7.I’ll go camping with you,if I _____ free tomorrow.
A.will be B.shall be C.am
请问为什么A、B不对

IF可引导条件状语从句.主句用一般将来式,从句要用一般现在式表将来式.
I will not go out if it rains tomorrow.