用to do,to have,to be,造句.写出at 同类词.

题目

用to do,to have,to be,造句.写出at 同类词.

答案

It’s my duty to do my homework.
I plan to have a-three-day holiday.
I want to be a basketball player.
at,in,on,under,
(都是介词,在什么里面、上面、下面.）