The teacher often makes him ___clean__ the blackboard.为什么要用clean,请说明
问题描述：
The teacher often makes him ___clean__ the blackboard.为什么要用clean,请说明
答
makes 是使役动词，后面him是宾语；clean是省略了符合to的不定式作了宾补，这是语法规定。
答
make sb do sth固定用法,让某人做某事