听下面一段对话，回答16至18三个小题。
()16. What does the girl want to know first?
A. How astronauts exercise in space.
B. How astronauts sleep in space.
C. How astronauts do experiments.
()17. How do astronauts chat with their families on Earth?
A. By sending letters.
B. By video calls.
C. By making phone calls.
()18. Why do astronauts look at stars more clearly?
A. There is no air around the Earth.
B. There is no dangerous energy.
C. There is no light from the sun.

16.A 17.B 18.A

听下面一段对话,回答19至21三个小题。
()19. Where did Peter work as a volunteer teacher last month?
A. In a city school in southeastern China.
B. In a primary school in a faraway village.
C. In a museum in his hometown.
()20. According to Peter, what does volunteering include besides donating money or things?
A. Teaching kids English and organising school trips.
B. Improving the local environment and helping people in need.
C. Building new houses for villagers and repairing roads.
()21. What made Peter come up with the idea of volunteering?
A. His father's volunteer experience at a museum.
B. A summer camp he joined in high school.
C. A teacher who encouraged him to help others.

19.B 20.B 21.A