Questions 4 to 6 are based on the passages you have just heard.
A. The combat against environmental pollution.
B. Problems caused by artificial lights.
C. Technical improvements of LED lights.
D. The importance of darkness to the ecosystem.
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Listen to the recording
Artificial lights can secure people’s safety in cities.
B. Lights make the view of universities more beautiful.
C. LED lights tend to use less energy than other lights.
D. Artificial lights in the city endanger people’s health.
Listen to the recording
A. They can help reshape ecosystem.
B. They are comparatively more expensive.
C. They are vastly deployed in 16 countries.
D. They are a major source of light pollution.
Questions 7 to 8 are based on the passages you have just heard.
A new technology to produce clean energy.
B. A new idea on ecosystem improvement.
C. A new chemical to better utilize sunlight.
D. A new method to ease global warming.
Listen to the recording
A. Some think it is impractical.
B. Some think it should be banned.
C. Some think it may threaten planes.
D. Some think it can reduce droughts.
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