理工类英语考试练习小题

理工类英语考试练习小题

　　阅读理解：

　　Heavy metals are persistent; they do not break down to other chemicals in the environment.Industrially polluted sites usually undergo intensive clean-up and rehabilitation because heavy metals are a health concern once they enter the food chain.Some trace metals are alleged to cause cancer and are also known to cause poisoning.

　　The main idea of this paragraph is__________.

　　A.The Nature of Heavy Metals

　　B.Potential Hazards of Human Contaminated Soils

　　C.Heavy Metals and Food Chain

　　D.Research on Channels of Heavy Metals Getting into Human Food Chain

　　正确答案：B

　　答案解析：本段文字讲的是：受到工业污染的土壤含有重金属，而重金属很稳定不容易降解，其中的某些微量重金属能使人致癌或中毒。可以看出其中心内容是：受污染土地的潜在危险，选择B。