He often make us ____(laugh).laugh为什么用原行不用to laugh.

题目

He often make us ____(laugh).laugh为什么用原行不用to laugh.
It's time for us_____(have) dinner.为什么用to have,不用have.

答案

make sb do sth 用动词原形作宾语补足语. 固定搭配.
It's time for sb to do .是某人做.的时候了.也是固定用法.