With the growth of human population,the number of species has decreased rapidly in America,and some species have even vanished from our planet.
There are several possible reasons for this.Above all,as the human population grows rapidly,a growing number of people came to live where some wild species have been living.Then these species have to move to other places.Some of them probably can not adapt to the new environment and die.
随着人口的增长，物种的数量在美国迅速减少，一些物种甚至在地球上消失了。
这有几个原因。首先，随着人口迅速增长，越来越多的人来到住在一些野生物种的生活。那么这些物种迁移到其他地方。他们中的一些人可能不能适应新环境而死亡。