In the 1980s, scientists around the world began to notice something strange: Frogs were disappearing. More recent research has shown that many kinds of amphibians are declining or have become extinct. They have been around for a long time - over 350 million years. Why are they dying out now?
The most serious aspect of amphibian loss, however, goes beyond the amphibians themselves. Scientists are beginning to think about what amphibian decline means for the planet as a whole. If the earth is becoming unlivable for amphibians, is it also becoming unlivable for other kinds of animals and human beings as well?
There are a number of other factors in amphibian decline. Pollution is one of them. In many industrial areas, air pollution has poisoned the rain, which then falls on ponds and kills the frogs and toads that live there. In farming areas, the heavy use of chemicals on crops has also killed off amphibians. Another factor is that air pollution has led to increased levels of ultraviolet light. This endangers amphibians, which seem to be especially sensitive to UV light. And finally, scientists have discovered a new disease that seems to be killing many species of amphibians in different parts of the world.
36 Losing amphibians means losing
B knowledge about air and water pollution.
D an opportunity to detect poisonous gases.
A in any stream they can find,
C only on sand.
38 The arroyo toad is disappearing because
B it is losing its habitat.
D it cant bear the cold of winter.
A poisonous gases.
C water leakage.
40 Scientists think that the decline of amphibians could
B cause a decline in other kinds of animals.
D be a good sign for human beings.
牛津版高三英语课件module10 Unit4 law and orde阅读
2010年山东省泰安市中考英语一模试题及答案
2010年山东省德州市乐陵中考英语模拟试题
高二英语unit3 language points课件
2010年洞头县中考英语模拟试题及答案
外研版初一英语上册教案Module9 Unit2 Is it an African elephant
冀教版七年级英语上册Unit 7 Lesson49 Season and Months教案
2010年南京市建邺区中考一模英语试卷及答案
七年级英语上册Unit5 Family and Home Lesson33-36教案
高二英语Unit11--Unit20检测试题及答案