是on this weekend还是at this weekend?急,考试必要,

都可以的!但是on 用的多一些.
on the weekend /at this weekend
在周末
例句:
The club got all the members together on the weekend.
俱乐部使全体成员在周末举行了一次联允.
We had a good time on the weekend party.
我们在周末聚会上玩得很快乐.
You may go grass skiing, bicycle riding, or shopping on the weekend.
周末你可以去滑草,骑脚踏车,或购物.
They live in London during the week and go to the country at the weekend.
他们从星期一到星期五都住在伦敦,周末到郊外去.
The office is closed at the weekend.
这个办事处星期六和星期日不办公.
`Where are you going at the weekend?' `Nowhere special (ie Not to any special place).'
‘你打算到哪儿去度周末?’‘无处可去.’