A．BCD编码
B．循环码
C．曼彻斯特编码
D．差分曼彻斯特编码
参考答案：C
解析：曼彻斯特编码规则：将每个码元分为两个相等的间隔，码元1的前半部分为高电平，而后半部分为低电平，码元0与码元1相反。差分曼彻斯特编码规则：若码元为1，则其前半个码元的电平与上一个码元朗电平一样；若码元为0，则其前半个码元的电平与上一个码元的后半个码元的电平相反。不论码元是1还是0，在每个码元中间的正中时间时刻，一定要有一次电平的转换。所以答案为C。
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| When you're invited to have dinner in a foreigner's home, please remember the following: At table, when the hostess (女主人) picks up her napkin (餐巾), you may pick up yours and put it 1 your legs. If a servant (佣人) passes 2 around, he will pass the dish to you at your left hand 3 you can easily serve yourself with your 4 hand. Never 5 yourself while the dish on your 6 ; it is then the turn of your neighbor on the right. Do not reach across the table or in front of someone to get something-that is not 7 . Ask him or her to pass it to you. There are things in the middle of the 8 , such as bread, butter, and candies. You shouldn't take any until the hostess tells the servant to pass 9 to you. Do not leave your seat without 10 anything. If you need to leave the table to go to the washroom or something else, you should say "Excuse me for a moment, please." | ||||
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