业务信道
参考答案：
基站和移动站之间传送数字信息的信道，用来传送用户信息和信令信息。
下列运算正确的是（ ）
A．（a-b）2=a2-b2
B．（-a2）3=-a6
C．x2+x2=x4
D．3a3•2a2=6a6
根据句意、首字母及汉语提示完成单词
1. There is a __________(桥) b__________ these two cities.
2. The post office is across f__________ the bank.
3. Where's the __________(超市)?
4. Just go s__________ and you'll see it.
5. Can you go to the p__________ office and send a letter for me?
6. Let's go a__________ the street.
7. The __________(银行) is near the hotel.
8. We often borrow books from the l__________.
