1.Some of the students used their mobile phones during class, while the others had their phones switched off.
switch off关闭
Please switch off the lights when you leave.
出门时请随手关灯 。
2.The head researcher, Dr Jeffrey Kuznekoff, said students who did not use their mobile phones while the teacher was talking got higher scores on tests they took at the end of the class.
at the end of在…结尾,在…末端
Only two go down at the end of this season.
本赛季末只有两支队伍降级 。