题目内容：

some children are playing ballgames near the lake. Their parents are __ them. They are happpy.
A. with B. join C. heop D. take part in

优质解答

A答案正确,一些小孩正在湖边玩儿,他们的父母和他们在一块,他们很开心.
join 和take part in 都有加入的意思,是行为动词,后半句中有 be动词,所以join 和take part in 放在此处都不合适,而 be with sb 表示 和某人在一起.