简述能引起传输误码率过高的原因。
参考答案:
接头不好、HDSL系统、线缆外皮划伤、与交流电交叉接地不好、光端机或微波线路不稳、时钟误差、外界干扰。
用所给词的适当形式填空。
1. I would like five ______ (tomato).
2. There aren't any ______ (noodle) in the bowl.
3. Have they got ______ (some) rice?
4. We have got some ______ (banana) on the table.
5. Do you like ______ (hamburger), Daming?
直流发电机E与Ia的方向:()
A.相同
B.相反
C.不一定