On Sundays there were a lot of children playing in the park, parents seated together joking.
A. whose
B. their
C. which
D. where
网友回答
A. whose
(答案→)B. their
C. which
D. where
解析：考查独立主格。句义：在星期天，有许多孩子在公园里玩，家长们坐在一起开着玩笑。把握逗号后的非谓语动词seated，这是关键词，由此确定是非谓语，而不是从句，所以A Ｃ D都不对，所以B正确。