根据课文内容,完成下列短文。

     When   1   ( compare) with most natural changes, that the temperature of the earth rose about one degree

Fahrenheit during the 20th century is quite shocking. And it's human activity   2   has caused this   3   (全球

的)warming rather   4   a random but natural   5   (现象): Dr Janice Foster explains that we add huge   6   of

extra carbon dioxide to the atmosphere by burning fossil fuels. From the second   7   (图表) and the discovery

of Charles Keeling, all scientists believe that the burning of more and more fossil fuels has resulted   8   the

increase in carbon diox ide. Greenhouse gases continue to build up. Some think that the trend would be a   9   (灾难). On the other hand, George Hamb ley  10   (声明) that more carbon dioxide would encourage a greater

range of animals and bring us a better life.