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.