[填空题]The greenhouse effect has warmed the Earth when the Earth came into being.

[填空题]The greenhouse effect has warmed the Earth when the Earth came into being.

[填空题]Without greenhouse effect, Earth would be colder by about ______.

[填空题]The greenhouse effect causes trouble by raising the temperature of the planet. The (1) rise is not very much, but the Earth’s ecosystem is very weak, and small changes can have large effects.
It has been believed that this (2) of one degree will happen by the year 2025. This could probably (3) the North American corn belt, which produces much of the world’s grain, (4) to much higher food prices, and even less food for the Third World than they already have. However, it would also mean that some countries which are further north would be able to (5) crops they had never been able to before, although there is less land as you move north from the corn belt.
The other serious worry is that rising sea levels from the melting of the polar ice could (6) flood many countries. A rise in sea levels of one meter, which many experts are (7) by the year 2100 (and some as soon as 2030), would flood 15 percent

[简答题]Such a greenhouse effect is created when energy in the form of sunlight easily passes through a planet’s atmosphere, warms its surface, and is converted to heat radiation that is then held in by the atmosphere.

[单项选择]A "greenhouse effect" will raise the earth’’s temperature enough by the year 2100 to cause dramatic climate changes, increase sea levels and disrupt food production, United States scientists said this week. 　　The earth’’s atmosphere is heating at a rate that could mean temperature rises of two degrees centigrade by the middle of the 21st century and five degrees centigrade by the year 2100, according to a report issued by the US government’’s Environmental Protection Agency (EPA). 　　"Substantial increases in global warming may occur sooner than most of us would like to believe," the EPA said. 　　The agency said the first effects might be felt as early as 1990, because temperatures would be rising more than seven times faster each decade between now and the year 2100 than they had been for the past 100 years. 　　"Temperature increases are likely to be accompanied by dramatic changes in precipitation and storm patterns and a rise in global average sea level," the EPA report said. 　　"A
A. the continents would be flooded within a century.
B. economic inadaptation would be inescapable.
C. world climate would return to that of the Ice Age.
D. Europe would sink to the bottom of the Atlantic.