41.  On my way to school it began to rain hard.When I got to the door of the our class room .

42.  So many people haven't realise the importance of protect the resource of water and waste or pollute water casually.

43.  In fact, fresh water are very lack of.

44.  Because there is more than 70 percent of surface covered with water on the earth, and we can make use of fresh water in the form of rain, river, well and so on.

45.  and it seems water is the first thing we shall never be lack of.

46.  Now fresh water that can be made use of is Decreasing.

47.  Through the observation of per 1,000 births, the infant mortality in 1960 is twice as much as it was in 1990 .

48.  Because these years, no big war happened in world, and all of the countries' people do their best to develop their own countries.

49.  In the result , the people's contrution of ???

50.  In the future, with the developing of the socity , the life of