我也不太懂 说Don't eat in the classrooms .这个“classroom”后为什么要加“s”?还

He eats in the classrooms为什么翻译中eat不加s Don't arrive late for class.Don't eat in the classrooms. "Don't eat in the classroom,Tom,'the teacher said. Jim,don't eat in the classroom .Please outside Don’t eat in the classroom.的同义句 Don't eat in the classroom 同义句 Don't eat in the classroom.中in the classroom是什么成分 Don't eat in the classroom .You must eat in the dining hall. Don't eat in the classroom.(改为同义句)___ ___ ___in the classroo Don't eat in classroom _don't fight.a.or Don’t eat or drink in the classroom.( 同意义改写) Don't eat or drink in the classroom.用should改写句子,意思不变,怎么改?