31.  you can sit under the tree, if you do that, the sun will not burn you.

32.  In addition, there is much water under the ground.

33.  Under the statement , We should save water.

34.  If the total water on the earth is 100%, while fresh water is only 3% including ice-beg , water deep under the land.

35.  They think it will rain at times, and the rivers are always full of fresh water as the lakes are, and we even can get the fresh water under the ground.

36.  Under this condition, many big cities are short of water.

37.  Different student has different choice under certain circustances .

38.  Meanwhile, new traffic projects are under consideration.

39.  For one hundred years, Hong Kong is under the control of British.

40.  The sky was high , no cloud under it .