参考答案：

The above graphs make it easy to draw a conclusion that the development of the US sees a growing population during nearly B00 years thanks to the progress in technology and economy. However, the development is achieved at the cost of some wildlife. As human population increases, the species of wildlife decreases, and some are even on the brink of extinction.

We may come up with a variety of reasons for this situation. But the most prominent one is human being’s weak sense of wildlife protection, which leads to the decrease of wildlife as a result of illegal hunting and killing of wildlife for profits. The destruction of ecological environment also aggravates the difficult situation. It is becoming even more difficult for wildlife to survive, with the gradual decrease of forest and pasture coverage area and the increase of pollution and soil erosion due to the explosion of population. Hence, unfortunately but naturally a soaring number of human population comes in tandem with a descending variety of wildlife.

The construction and protection of ecological environment is a pressing and long-term task. To tackle the problem, the US government needs to enhance people’s awareness of wildlife protection and even the support of some relevant laws and decrees. What’s more, it should make more investment in the wildlife protection sector in a bid to create a better environment for the living wildlife to coexist harmoniously with human beings.