看图补全对话。

Tom: Hello, this is Tom speaking.

Grandma: Hi, Tom, this is grandma. What is your mother doing?

Tom: My mother is c_____________.

Grandma: What is your father doing?

Tom: My father is s_____________ on the sofa.

Grandma: What are you doing, Tom?

Tom: I am d_____________ my homework.

Grandma: Good boy! What are Peter and Cindy doing?

Tom: Peter is d_____________ on the wall (墙壁) and Cindy is c_____________.

Grandma: Oh, my goodness (天哪)!

中低压串联离心泵由两个独立泵腔组成，一是（），二是（），中间用隔板分开。

A.低压泵室

B.中压泵室

C.中高压泵室

D.高压泵室