TPO39-L4
Potential Alternative Source
Listen to part of a lecture in a biology class.
- What is the discussion mainly about?
- A. Advantages of cellulose over traditional sources of fuel.
- B. A recent study about microorganisms that process cellulose.
- C. Some newly discovered characteristics of cellulose.
- D. Challenges involved in converting cellulose into fuel.
- According to the speakers, why is cellulose such a significant potential source of energy?
- A. Because it is so abundant in nature.
- B. Because it is so easily created in a lab.
- C. Because its enzymes have so many uses.
- D. Because it can be processed in just a few steps.
- What is the professor’s opinion about corn-based ethanol?
- A. She thinks using it in motor vehicles may harm the environment.
- B. She thinks it is not an energy-efficient alternative to gasoline.
- C. She thinks it will eventually become cheaper to produce.
- D. She thinks researchers should invest more in its development.
- The professor describes the current method for producing cellulose ethanol. What are the two important steps she mentions?
[CHOOSE 2 ANSWERS]
- A. Yeast is added to cellulose to create an enzyme.
- B. An enzyme breaks down cellulose into sugars.
- C. Microorganisms ferment sugars into alcohol.
- D. Ethanol is extracted from certain microorganisms.
- What does the professor imply about a superbug?
[CHOOSE 2 ANSWERS]
- A. It will be an altered version of a naturally occurring organism.
- B. It was discovered as a result of looking for new sources of cellulose.
- C. It may contribute to the development of an efficient way to produce ethanol
- D. It may produce many kinds of alternative fuels.
- Why does the professor says this: 🎧
- A. To emphasize the necessity of working to preserve rare species.
- B. To suggest that the company will never find what it is looking for.
- C. To emphasize that bacteria that break down cellulose are too rare to be useful.
- D. To indicate that she endorses the company’s strategy.
答案：
D A B BC AC D