We will have a party ____ this week,but they will have one ___ next week A.on'to B.in;/ C./;/ D/;on

问题描述:

We will have a party ____ this week,but they will have one ___ next week A.on'to B.in;/ C./;/ D/;on

DWhy?这周我们要开一个聚会 this week 前不加