参考答案和解析
正确答案：
Disappearing Forests The world’s forests are disappearing. As much as 1/3 of the total tree cover has been lost since agriculture began some 10,000 years ago. The remaining forests are home to half of the world’s species, thus becoming the chief resource for their survival. An increasing amount of forestland has been used for industrial purposes or for agricultural development such as crop-growing. By the 1990’s less than half of the earth’s original rain forests remained, and they continued to disappear at an alarming rate every year.
解析：
暂无解析
