以下哪种机制可在无信息传输时,通过发送伪随机序列信号,使非法监听者无法知道哪些是有用信息,哪些是无用信息:( )
A. 公证机制
B. 鉴别交换机制
C. 业务流量填充机制
D. 路由控制机制
In my job, I am _________ buying the raw material necessary for the car production.
A. take responsibility of
B. responsibility in
C. responsible for
D. responsible in
I _________ finding the best material at the best price.
A. proud in
B. proud of
C. make pride in
D. take pride in
The _________ of our production means we have cheap products.
A. efficiency
B. affection
C. effect
D. affect
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