At the --- (weekend),he helps his parents do farm work. 按照适当形式填空 再说下原因

at the weekend造句 at the weekend同义词 on the weekend or at the weekend 我们说 on weekend ,at weekend,还是in the weekend 一下短语有什么用法区别?At weekend.On weekend.At the weekend.On the weekend. At weekend和at the weekend有区别吗?同上. at weekends和at the weekend 区别 at the weekend 和 over the weekend 有什么分别? at the weekend 和 on the weekend的区别 at the weekends和at the weekend和at weekend和at weekends有什么区别 at the weekends,at weekends,at the weekend,at weekend 怎么区别? on the weekend和at weekend用法一样吗? at weekend,on weekend,at the weekend ,on the weekend和on weekends的区别?尽量详细些... on the weekend/ in the weekend/ at the weekend.三个短语怎么区别? What do you do at the weekend? What do you ____do at the weekend? What do they do at the weekend? What did they do at the weekend?