听第二篇短文，回答第 16 至 20 小题。
(
)16. What was Leo worried about at first?
A. The high cost of electricity.
B. The pollution from a factory.
C. The lack of recycling bins in his town.
(
)17. What did Leo's family decide to do to make a change?
A. They bought an electric car.
B. They volunteered at the solar farm.
C. They put up solar panels on their roof.
(
)18. What did Leo do at his school?
A. He started a club.
B. He organized a competition.
C. He raised some money.
(
)19. What kind of clean energy is NOT mentioned in the text?
A. Sun.
B. Wind.
C. Water.
(
)20. How did Leo feel at the end of the story?
A. Surprised and confused.
B. Tired but satisfied.
C. Hopeful and optimistic(乐观的).
