Mary will come to help me.she will be free tomorrow.改为含if条件状语从句的复合句
问题描述：
Mary will come to help me.she will be free tomorrow.改为含if条件状语从句的复合句
答
Mary will come to help me if she is free tomorrow.
当主句是一般将来时,条件状语从句要用一般现在时.——主将从现