31.  it is using the language, thinking in it and talking in it all the time: if people use a second language all the time, they will learn in quickly.

32.  there are three of the biggest man-made projects in the would .

33.  And water in river and in well is also adequate.

34.  In above graph, we can find the fact that in 1960, life expectancy was 40 years old and in 1990, 60 years old, while infant mortaility was 200 deaths per 1,000 births in 1960 and 100 deaths per 1,000 births in 1990.

35.  When we talk about the grobal shortage of fresh water, some people May be surprised; We have lots of fresh water, the water in river , the water in well and rain-water are all fresh water, how can we use it up ?

36.  There are full of water in our would .

37.  In the recently years .

38.  If you think these are not enough you can get out in to the street , use your eyes and ears, obverse the society .

39.  we could listen to the radio to know the incidents happened in and outside our nation.

40.  In generally , we should practise in the society.