Other major sources of energy have their own benefits—and their own set of risks. Oil is limited, likely to be affected by political pressure and rising prices, and has caused serious environmental disasters of its own. Coal is blamed for serious air pollution, and mining for coal is an often perilous profession: coal mining accidents from Colombia to China have resulted in thousands of deaths. Natural gas pollutes the air less than oil or coal, but old and leakprone(容易泄漏的) natural gas pipelines can explode, killing and injuring dozens of people. Water power is a renewable and clean source of energy, but building dams requires a lot of land, and if they burst, the environmental damage is widespread.
文章大意：本文是一篇说明文。作者通过列举核能、石油、煤、天然气、水能的优缺点，说明了任何一种能源都有其危险的一面。
1．It can be inferred from the passage that ________.
A．nuclear energy is a doubleedged sword
B．the demand for nuclear energy is declining
C．the nuclear disaster in Japan meant the end of nuclear energy
D．nuclear energy produces onethird of the world's electricity supplies
答案：A 推理判断题。根据第二段可知，一方面原子弹的使用致使数十万人死亡，整座城市被毁，另一方面核能源给人类提供了近14%的电能。由此可知，核能是一把双刃剑。故选A。
