Energy recycling ( 能量再利用)① Every

Energy recycling ( 能量再利用)
① Every day, people throw away a lot of rubbish. Some of the rubbish, such as food, paper and iron, rots away over a long period of time. But plastics and rubber never rot. If they are burned, they give off poisonous gases. How to get rid of these things is a big problem.
② Fortunately, people are beginning to realize just how serious the whole situation is. In many countries, laws have been passed to prevent factories form sending out poisonous gases and polluted water.
③ Many natural materials are becoming scarce. Scientists have found ways to take some useful things out of the waste materials and use them again. This is called recycling. Steel, iron, glass, cloth and paper can all be recycled.
④ Waste water, too, can be recycled. When the waste water from factories is made clean and reused, a lot of money is saved. Waste water from a number of cities is “cleaned” before flowing back into rivers. Today, many rivers that were polluted are getting cleaner and cleaner. Fish and birds are returning to these rivers, and the water in them is no longer poisonous or dangerous to people’s health.
⑤ Man is fighting a battle against pollution. Yet, the battle will not be won until everyone knows how serious the danger is, and does something to stop it.
前5道题选项：
A. Water recycling
B. Rubbish problem
C. Fighting pollution
D. Serious situation
E. Material recycling
F. Environment protection
后5道题选项：
A. recycling
B. polluted water
C. poisonous gases
D. pollution
E. people’s demands
F. a lot of money

Paragraph④: ____.
【正确答案】：A
【题目解析】：从本段第一句的总起句直接判断出此段讲的是水的回收利用，答案是A。