共有 4 个站进行码分多址 CDMA通信。四个站的码片序列为:A (-1-1-1+1+1-1+1+1)B(-1-1+1-1+1+1+1-1)C(-1+1-1+1+1+1-1-1)D(-1+1-1-1-1-1+1-1)收到这样的码片序列: (-1+1-3+1-1-3+1+1)。请问哪几个站发送数据了?
A、B、C
B、C、D
C. A、B、D
D. A、C、D
查看答案
物理层的协议数据单元( Protocol Data Unit ,PDU)是什么?
A. 比特流 (Bits)
B. 帧( frame)
C. 分组( Packet)
D. 分段( Segment)
Choose the answer that correctly interprets the sentence from the text.Too many baby-boomer parents are overly concerned with success. They just don’t want to let go.(para16)
A. Too many baby-boomer parents care too much about success. They just don’t want to let go.
B. Too many baby-boomer parents are overly concerned with their children. They just don’t want to let them go.
The first-year experience is exciting, liberating and terrifying, all combined to help us grow into adulthood. That is, if our parents don’t come with us.(para 4)
A. The first-year experience is exciting, liberating and terrifying, all combined to help us grow into adulthood. That is going to happen if our parents don’t come with us.
B. The first-year experience is exciting, liberating and terrifying, all combined to help us grow into adulthood. That is to say, if our parents don’t come with us.
The woman behind the counter clearly felt, as I did, embarrassed for this young man, who was accompanied by his no doubt well-intentioned, but misguided, father. (para 5)
A. Just like I did,the woman behind the counter clearly felt embarrassed for this young man, who was accompanied by his no doubt well-intentioned, but misguided, father.
B. I saw that the woman behind the counter did feel embarrassed for this young man, who was accompanied by his no doubt well-intentioned, but misguided, father.
微信支付 
支付宝支付