He wants to be a teacher after _(leave) school.

问题描述:

He wants to be a teacher after _(leave) school.

leaving (after后用动名词形式)

leaving
介词后面要动词的ing形式

He wants to be a teacher after (leaving) school.
句意:他毕业后想当老师.
介词after后要用动名词形式,也就是动词原形加上ing.