(the pupils) are having a PE lesson on the playground.对括号里提问要理由
问题描述：
(the pupils) are having a PE lesson on the playground.对括号里提问要理由
答
Who are having a PE lesson on the playground?
对主语提问（且是表示人时）直接用who
你要快点采纳哟,老师批be动词are是错的。不知道怎么用be动词。BE（are is am)就这三个，一定不是am学生是复数，其实用ARE没什么问题你老师的选项应是is,如果不看原句，用is更合理些.