完成句子，使改写后的句子完整，并与原句意思相符，注意每空只填一个单词。

1. What’s your last name?

What’s your ________ ________?

2. Can I help you?.

______ can I _______ for you?

3. Thank you for your letter.

_________ for _______ a letter to me.

4. How much are the pants?

_______ __________ ________ ________ these pants?

5. He often helps me with English.

He often helps me ______ _________.

变电设备在线监测系统的组成部分（）。

A.监测装置

B.综合监测单元

C.站端监测单元

D.信息一体化平台