Question

On sunday there were a lot of children playing in the park _ parents seated together joking选什么

A。there B.whose C which D that

Answer 1

a 因为seat是及物动词，不做谓语，是过去分词。所以这里逗号后面的句子是独立主格，不是非限定性定语从句。

Answer 2

是A没错

Answer 3

B

Answer 4

C

Answer 5

B.whose

追问

不好意思，各位A是their，可以请你们再次回答么

追答

那就是a。
On sunday there were a lot of children playing in the park （with ）their parents seated together joking。
因为seated是修饰parents的。