听力音频：
L1
讲座
1. What is the discussion mainly about?
The economic consequences of putting restrictions on coal-burning factories
Alternatives to geoengineering that are economically feasible
Arguments that geoengineering might contribute to global warming
The cost-effectiveness of using geoengineering to reduce global warming
2. What is an advantage of having a large amount of algae in the oceans?
It can lead to decreased amounts of carbon dioxide in the atmosphere.
It can prevent ocean temperatures from increasing rapidly.
It can absorb large quantities of pollutants from the water.
It can help scientists monitor the effects of global warming.
3. What is one proposal in the article that addresses climate change?
Adding iron particles to the stratosphere
Moving a specific gas from the lower atmosphere to the stratosphere
Placing greater restrictions on businesses’ use of energy
Requiring consumers to use renewable energy
4. According to the discussion, what are some concerns about the proposal to move sulfur dioxide to the stratosphere?（多选题）
There is conflicting information about the quantity of sulfur dioxide that would need to be moved.
Funding for the project has not yet been approved.
The balance of gases in the stratosphere would need to be carefully maintained.
Monitoring for unintended consequences can be expensive.
5. Why does the professor talk about motion detectors that control lights in a room?
To introduce the topic of the effect of energy consumption on climate change
To inform the students that they no longer need to turn the lights off when they leave the classroom
To suggest that there may be alternative ways to solve complex problems
To give an example of a recent, successful geoengineering project
6. Why does the professor say this:
To indicate that he is puzzled by the student’s question
To indicate that he agrees with the student’s criticism of the author
To indicate that he believes it is possible to predict climate change
To persuade the class that the author has made a valid point
