Semester seriously alive
Have time on one‘s hands
Get the most out of sth.
Run out （of）
1.It is like a drug. The more time you waste， the easier it is to go on wasting time.
2.If you seriously wish to get the most out of college， you must put the time message into practice.
3.How much study time you plan for each classroom hour depends on four things.
4.This will not only keep the study habit alive but also keep you up to date on your class assignments.
5. It is a good day to catch up on back reading and other assignments.
back的用法（back rent back pay back taxes）