On Sundays there were a lot of children playing in the park parents seated together joki

问题补充：

On Sundays there were a lot of children playing in the park, parents 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：考查代词。根据后面句中用了分词可知，考查独立主格结构，故选A。