环境科学
TPO53-L2 Two Kinds of Pollution
Listen to part of a lecture in an environmental science class.
- What is the lecture mainly about?
- A. The difference between point source and non-point source pollution
- B. The source and treatment of a serious type of pollution affecting the Chesapeake Bay
- C. The causes for the large decrease in algae in the Chesapeake Bay
- D. The development of farming methods during the past century
- What is one of the reasons that the professor mentions pollution that comes from a pipe?
- A. To compare point source pollution with non-point source pollution
- B. To blame factories and sewage treatment plants for producing most water pollution
- C. To demonstrate that agricultural runoff is a point source pollutant
- D. To suggest new methods that may someday begin to reduce water pollution
- According to the professor, why has it been difficult for fish and many other organisms to live in the Chesapeake Bay?
- A. Toxic chemicals in the water have poisoned many of them.
- B. Runoff from farmland has made the water very muddy.
- C. Water flow from streams has been unreliable.
- D. Oxygen levels in the water have been reduced.
- What is the professor’s attitude about the use of chemical fertilizer?
- A. She is surprised that some farmers have stopped using it.
- B. She is convinced that its use should be increased substantially.
- C. She worries that farmers may be using too much of it.
- D. She regrets that it was not more useful for increasing crop production.
- What two practices does the professor suggest for reducing the amount of nitrogen that enters a bay such as the Chesapeake?
[CHOOSE 2 ANSWERS]
- A. Planting trees along the sides of streams
- B. Building water treatment facilities where streams enter the bay
- C. Planting cover crops that take up excess nitrogen in the soil
- D. Letting farm animals graze in areas near streams and the bay
- According to the professor, why were farmers reluctant to create buffer zones near streams?
- A. They were not convinced that buffer zones effectively control pollution.
- B. They feared that creating buffer zones might decrease farm income.
- C. Government approval for creating buffer zones was at first difficult to obtain.
- D. Planting trees was much more expensive than planting the usual crops.
