It's surprising that Tom doesn't know what homework(to do)after s_英语解答

It's surprising that Tom doesn't know what homework(to do)after school.请问为什么要用to呢?

人气：169 ℃　时间：2020-04-01 01:48:38

解答

因为这是不定式作know的宾语,具体地说,就是:疑问词组(what homework )+to do 作宾语.表示还没发生的动作.
不定式的构成就是:to +动词原形,因此必须用to