21.  We must make full use of it.

22.  We should make full use of water.

23.  I think we should make full use of a drip of water.

24.  We should make full use of water and must not waste the water!

25.  In my opinion, above all, I will make full use of the classtime to learn basic knowledge.

26.  We should make full use of college life.

27.  First we must make full use of water, don't waste it .

28.  At first, we should make full use of time to study.

29.  But we can't keep time from passing, what we can do is to make full use of time to study and not to pass up a chance to improve our knowledge and ability .

30.  So for the toppest grade, I have to make full use of time, must study harder than before.