Directions：Write an essay based on the following chart.In your writing you should
1） interpret the chart，and
2） give your comments
This is a （set of） simple but informative chart（s），which explicitly illustrate（s） the changes in American population and the number of species in the past centuries / the degrees of different age groups of employees’ satisfaction with their jobs in a certain company / the changes in the market share of some brands in Chinese auto market in the past years /the situation of students taking part-time jobs in a particular university.
折线图：broken line chart
As can be seen in it，the U.S. population soared from a little more than zero in 1800 to 240 million in 1990，while the number of species that have become extinct rose from none in 1600 to 70 in 1900.
As can be seen in it，the expenditure basically falls into four categories：new year gifts account for 40%；traffic makes up 20%；meals compose another 20%，and the rest constitutes the last 20%.
Evidently，the chart is aimed at drawing people’s attention to environmental protection.
Obviously，the chart is meant to reveal problems existing with the management of the company.
Apparently，the chart refers to the fact that homemade cars are gaining population in China.
Apparently，the chart reveals the fact that an increasing number of college students are involved in part-time jobs.
A number of factors may account for the phenomenon revealed by the chart，but the following might be the critical ones.A fundamental cause，I believe，is the fast expanding economy.
Due to the need to develop agriculture and industry to meet the needs of increasing human population，man has occupied，destroyed or polluted the living space of other species.Another leading reason is the fact that relevant laws or regulations do not exist or are not severe enough.Therefore，some people kill wild animals for money without any fear. Last but not least，there has been a lack of relevant education in this field.
A number of factors may account for the phenomenon revealed by the chart，but the following might be the critical ones.A fundamental cause，I believe，is the fast developing science and technology in China，which has considerably lowered the price of homemade cars and improved their quality at the same time.
Another leading reason is the fact that the government has taken measures to encourage the development of national auto industry. Last but not least，people have attached more importance to supporting native products.
In fact，the phenomenon revealed by the chart has both advantages and disadvantages.On the one hand，it has brought along a number of benefits.Undertaking part-time jobs can not only provide students with opportunities to learn about society but also alleviate their parents’ financial burden.
In view of the seriousness of the problem，effective measure must be taken before things get worse.In the first place，it is imperative that the management of the company should lead the whole staff to drag the company out of the present trouble.
In view of the benefits of the tendency，effective measures must be taken maintain it.In the first place，it is imperative that pertinent policies should be worked out and implemented to further support national car industry.In the second place，a deep-going，widespread and ever-lasting campaign should be launched to enhance people’s awareness of supporting native goods.Only with these measures taken can we expect a brighter future.
To sum up，college students taking part-time job should be viewed as a two-edged sword，which presents both benefits and troubles.But we should not give up eating for fear of choking.The best policy，as I see it，is to maximize its advantages and eliminate its unhealthy influence，so that it can serve us in a better way.