My parents buy a preset ____ my birthday every year A to B of C for D on

问题描述:

My parents buy a preset ____ my birthday every year A to B of C for D on

on

for

C.for
注:1.应该是 present
2.为某日子或某人买什么东西的固定词组:buy something for.

D.on 特指在生日当天