新编六级听力练习 第304期

Passage Two
29.
A. It is extremely dangerous to fly in the dark.
B. Noise regulations restrict the hours of airport operation.
C. Some of its runways are not in good condition.
D. Cargo planes produce more disturbing noises at night.
30.
A. It might increase airport capacity.
B. It might lower property values.
C. It might lead to effective modification of existing jet engines.
D. It might cause more transportation costs to and from airports.
31.
A. The effects of noise on the quality of life.
B. The role of air traffic restrictions.
C. The production of quieter engines.
D. The economic aspects of noise reduction.