听下面一段对话，回答第1~2题。
1. What are the speakers talking about?
A. The role of water in our life.
B. The importance of machines.
C. A way of producing electricity.
2. Why is the wall so tall?
A. To produce more electricity.
B. To make the river beautiful.
C. To make the lake look bigger.

1.C 2.A

听下面一段对话，回答第3~4题。
3. What is the girl doing?
A. She is buying a book about a scientist.
B. She is working with a famous scientist.
C. She is reading a magazine about a scientist.
4. What can we learn about Nikola Tesla according to the talk?
A. He was the inventor of radios and televisions.
B. He was not clever but hard-working and successful.
C. He played an important role in the electricity technology.

3.C 4.C

听下面一段对话，回答第5~6题。
5. What does the woman speaker think of the man's idea on electricity?
A. She doesn't agree on it.
B. She thinks it is a good idea.
C. She doesn't show her opinion.
6. What will the man speaker buy?
A. A school bag and some salt.
B. A school bag and some batteries.
C. A bag of batteries and some salt.

5.B 6.C