北师大高中英语模块1Unit3Lesson4: Enough snow to make snowmen, and to have exciting snowball fights in the school playground.中in the school playground应为on the school playground吗？

解释：

表示“在运动场(上)”“在操场(上)”playground前既可用in，也可用on，但以用in为普通：They are playing baseball in [on] the playground. 他们在操场上打棒球。《英语基础词汇用法词典》

实际上，美国英语中通常用in the playground；英国英语中通常说on the playground，意思无区别。