to spend all of time on their study. As an old saying goes: All work and no play makes Jack a

dull boy.

一份适当的业余工作并不会占用学生太多的时间，事实上，把全部的时间都用到学习上并不健康，正如那句老

话：只工作，不玩耍，聪明的孩子会变傻。

Despite many obvious advantages of bicycle, it is not without its problem.