2、And with the development of Chinese economy, that policy also omproved city dwellers' lives greatly.(原因2)
　　　　　　3、Furthermore, the high-tech introduced made it possible for the country's economy as a whole to take off. (原因3)
　　　　　　4、All these result in the great fall of the Chinese population below the poverty line.

　　第三段：提出解决办法
　　结尾句： However, a further decrease in the number of poverty-stricken people is faced with some problems.
　　扩展句：1、With quite few employees being laid off, the effect of which is not only discouraging, but also challenging.
　　　　　　2、So my principle is to pay due attention to the "newcomers", but not just to care for the poor, say , in remote mountain areas.

　　第三部分、范文
　　As the bar chart shows, the number of people below the poverty line decreased dramatically during the years of 1978 to 1997.As early as 1978, about 250 million people were under the poverty line.Then seven years later, the number became three fifths that of 1978.And arriving in the year 1997, the number was reduced to 50 millions.　　　

　　Several factors contribute to the sharp decrease of the below-poverty population. The reform and opening following 1978 enabled the peasants to become much better off.And with the development of Chinese economy, that policy also omproved city dwellers' lives greatly.Furthermore, the high-tech introduced made it possible for the country's economy as a whole to take off.All these result in the great fall of the Chinese population below the poverty line.

　　However, a further decrease in the number of poverty-stricken people is faced with some problems.With quite few employees being laid off, the effect of which is not only discouraging, but also challenging.So my principle is to pay due attention to the "newcomers", but not just to care for the poor, say , in remote mountain areas.