Conversation One
19.
A. She is environmentaly-concerned.
B. She wants to save money.
C. Her car is being repaired in the shop.
D. She wants to see the man on the bus.
20.
A. Diana believes the air is not likely to be cleaner.
B. Diana thinks the diesel（柴油机） bus is free of pollution now.
C. Diana has taken a class on environmental engineering.
D. Diana sounds pessimistic about the future of the insulator（绝热器）.
21.
A. It makes the fuel burn more efficiently.
B. It helps release more unburned fuel.
C. It is easy to install.
D. It is very cheap.
22.
A. Lowering transportation fees.
B. The environmental engineering class.
C. The man's car in the shop.
D. Better environment.
