听下面一段对话,回答16至18三个小题。
()16. What is the shape of ginkgo tree leaves?
A. Round.
B. Fan-shaped.
C. Heart-shaped.
()17. Why do butterflies fly around flowers?
A. To catch sunlight.
B. To help the flowers.
C. To play with other butterflies.
()18. What might the speakers do later in their lives?
A. To plant more flowers.
B. To keep some butterflies at home.
C. To buy more ginkgo trees.

16.B 17.B 18.A

听下面一段对话，回答19至21三个小题。
()19. What does the rainwater collection system do?
A. It makes electricity.
B. It waters plants.
C. It cleans the air.
()20. Why did the students build birdhouses?
A. To provide homes for birds.
B. To study bird behaviour.
C. To decorate the garden.
()21. What is the conversation mainly about?
A. Reasons for tree planting.
B. Nature activity of the school.
C. Ways to protect animals.

19.B 20.A 21.B

听下面一段独白,回答22至25四个小题。
()22. What do guide dogs help blind people do?
A. Cook meals.
B. Walk around safely.
C. Read books.
()23. What can rescue dogs do?
A. Save people in need.
B. Visit sick children.
C. Fight fires.
()24. How do therapy dogs help people?
A. By providing medical treatment.
B. By reducing stress and anxiety.
C. By teaching new skills.
()25. What is the main purpose of the text?
A. To explain how dogs act.
B. To compare dogs with other animals.
C. To describe different ways dogs help humans.

22.B 23.A 24.B 25.C