i saw him ------his homework just now .应填do 还是 doing

问题描述:

i saw him ------his homework just now .应填do 还是 doing

doing
我刚刚看见他正在做作业

doing
see sb. do sth. 是强调动作已经发生了,是瞬间
see sb. doing sth. 是强调动作正在进行,是一个过程