将三相电源三个绕组的首末端依次相连，再从三个连接点引出三根端线就是三相电源的（）

A.星形联接

B.三角形联接

C.Z形联接

词汇运用10分

1. You can see the ______ (快乐) on her face because she can’t find her lovely dog.

2. The best ______ (决定) you can make is to learn how to get on well with them.

3. Listening to music or visiting interesting places can make you forget you _ (悲伤 ).

4. Enough sleep can make me feel _____ (有能量) and make me study better.

5. She feels unhappy today because she has a terrible ______ (牙痛)。

6. Can this kind of computer be _____ (可获得的) in the nearest supermarket?

7. The man we saw yesterday is so ______ (幽默) that we all like him very much.

8. It was difficult to _____ (解释) the problem to beginners. 

9. If you are free, go and have my bike ______ (修理).

10. Let’s send him some flowers. I’m sure that ______ (加油) him up.