21.  On the surface of the river twated something dirty and dead fish.

22.  With these words he quickly took off his own jacket and quickly handed it to me "Now take off your wet coat and put this one on to you'll get ill?

23.  On the other hand, for example, if you want to learn singing or dancing, you only know how to sing or how to dance and don't want to practise .

24.  Take a man who didn't play basketball stand on the two score line .

25.  There are many students, who never go out to the world and get to know the world, will feel difficult get on well with work mates and boss and raise their working ability .

26.  First, we should make everyone realize the shortage of fresh water, call on people don't waste water .

27.  On other hand, water that industry needs is increasing too.

28.  I will read newspapers that I can get my hand on.

29.  on the other hand .

30.  They will play truant of some subsidiary courses, skip over the substance which will not be tested on.