Also,we never visit a friend's house without calling first.We usually make plans to see friends
问题描述：
Also,we never visit a friend's house without calling first.We usually make plans to see friends
改为复合句
Also,we never visit a friend's house______________call first
答
we usually make plans to see friends whose house we never visit without calling first.Also,we never visit a friend's house______________call firstunless we make plans and 浪费不少脑细胞，强烈要求加分！