On Sundays there were a lot of children playing in the park and parents were seated toge

问题补充：

On Sundays there were a lot of children playing in the park, and parents were seated together joking.

A. their

B. whose

C. which

D. that

答案：

(答案→)A. their

B. whose

C. which

D. that

解析：因为句中有并列连词and，整个句子为并列句。