声压的表示符号为______，单位是______，用符号______表示。
参考答案：p；帕；Pa
阅读理解，根据对话回答问题。
Chen: What are you going to do this weekend?
Sarah: I'm going to plant trees.
Chen: Plant trees?
Sarah: Yes, I need some plants. So I'm going to the plant shop. What else? Let me see...
Chen: Are you going to use any books?
Sarah: Yes. I'm going to the bookstore. I'm going to buy a magazine about plants.
Chen: That's great!
Sarah: I want to be a science teacher one day!
1. What is Sarah going to do on the weekend?
She is going to .
2. Where is Sarah going to buy the plants?
.
3. What is Sarah going to buy in the bookstore?
4. What does Sarah want to be in the future?
She wants to be .
A．，正电荷
B．，正电荷
C．，负电荷
D．，负电荷
，正电荷
，正电荷
，负电荷
，负电荷