请帮我做几道英语关于动词的选择题，并做简要分析。谢谢！

C came into 解释：saw为过去时，因此时态要一致。
B to eat 解释：to不定式短语还有代表将来要做的事情，即这件事还没做，要做
A to do 解释： ask sb to do sth 固定搭配 让某人做某事

1.I saw the train( A )the station.
A. come into B.to come into C.came into D.to came into
2.The first thing I want to do is( B )
A.visit to him B.to eat C.ate D.eat
3.He asked us ( A ) it again.
A.to do B.do C.doing D.did
NO1.
1. see sb do sth 看见某人做过某事，
I often see him draw a picture.
2. see sb doing sth 看见某人正在做某事。
When I pass the window I see him drawing a picture.
3. be seen to do ,用于被动语态还原to
He is seen to draw a picture.
NO2
两个动词不能用在一起。“我想做的第一件事是吃。”is后面跟动词要加不定式to
NO3
ask sb to do sth 固定搭配。

A 同一个句子只能出现一个动词过去式，所以排除C。see sth doing 是看到某人正在做某事　或者 see　somebody　do　sth　看见某人做某事．
B　is　后接动名词或者名词或者to形式
A　ask　somebody　to　do　sth　

1;C 省略that 引导宾语从句
2；B to do 表目的
3；A ask sb。（not）to do sth。 固定搭配

C came into
B to eat
A to do

CDA