在操场上用in还是on

playground前用介词on还是in我们查到手头的一本金盾出版社出版的《英语基础词汇用法词典》(周贞雄编著)，该书认为：表示“在运动场上”或“在操场上”，playground前既可用介词in也可用介词on，但以用in为普通，并举如下：The children were all in [on] the playground. 孩子们都在操场上。

They are playing baseball in the playground. 他们在运动场上打棒球。

The sports meeting was held on the playground. 运动会在操场上举行。