A．铝块
B．铜块
C．空气
D．水
答案：C
非负数就是正数，非正数就是负数[ ]
Read and complete. 补全对话。
A: Are you ?
B: Yes, I am very hungry. I want to eat a pizza.
A: I want to eat a , too. I like on it. Do you like pepper, too?
B: Yes. Would you like some juice?
A: No, . I'd like some milk.
B: You don't like , but I like it.
