补全对话。

A: Excuse me.     1    ?

B: Sorry, I'm new here. You can ask my friend. He may know.

C: The Children's Hospital? Er …It's a little far from here.

A:     2    ?

C: It's about 5 kilometres away.

A:     3    ?

C: Yes, the No. 15 bus will take you there.

A: Where is the bus stop?

C:     4   and take the first turning on the right. You can see it on your left. You can't miss it.

A:    5    .

C: You are welcome.

1.                          

2.                             

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4.                          

5.                          

离心泵的泵壳的作用是（）。

A、避免气缚现象

B、避免气蚀现象

C、灌泵

D、汇集和导液的通道、能量转换装置