自考《英语(二)》试题练习:概括大意(1.22)
单选题
[概括大意]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