单选题
The greenhouse effect causes trouble by raising the temperature of the planet. The 30 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 31 of one degree will happen by the year 2025. This could probably 32 the North American corn belt, which produces much of the world's grain, 33 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 34 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 35 flood many countries. A rise in sea levels of one meter, which many experts are 36 by the year 2100 (and some as soon as 2030), would flood 15 percent of Egypt, and 12 percent of Bangladesh. The Maldives in the Indian Ocean would almost 37 disappear. Most of the countries which would suffer most from a rise in sea levels are the poor 38 states, so the islands in the Caribbean, South Pacific, Mediterranean and Indian Ocean have formed the Alliance of Small Island States, AOSIS, so they have a 39 voice in international politics and can make the richer developed world listen to their problems. A. severely B. damage C. island D. critical E. grow F. mainland G. louder H. predicting I. rise J. completely K. geometry L. actual M. extending N. leading O. develop