学生们通常在下午四点锻炼,(锻炼用exercise) The students usually --- --- --- 4 in the afternoon

问题描述:

学生们通常在下午四点锻炼,(锻炼用exercise) The students usually --- --- --- 4 in the afternoon
三个空

have exercise at为什么不是has?前面是students啊student+s表复数