更多"DCD://Data Carder Detect，载波侦测指示，有时简"的相关试题:
[填空题]DCD://Data Carder Detect，载波侦测指示，有时简称CD(Cartier Detect)。当调制解调器收到对方调制解调器送来的信号(载波Carrier)时，此灯会亮，代表已能和对方调制解调器传送 【20】 。
[单项选择]
A （） is a data type whose major attributes are determined by the roles governing the insertion and deletion of its elements. The only element that can be deleted or removed is the one that was inserted most （） . Such a structure is said to have a last-in/first-out (LIFO) behavior, or protocol.
A （） is a data type whose major attributes are determined by the roles governing the insertion and deletion of its elements.
A. stack
B. queues
C. pointer
D. record
[单项选择]E1载波的数据速率是（）Mb/s，T1载波的数据速率是（）Mb/s。
A. 1.544
B. 2.048
C. 6.312
D. 8.448
[单项选择]在E1载波中，每个子信道的数据速率是 (28) ，E1载波的控制开销占 (29) 。
A. 32kb/s
B. 64kb/s
C. 72kb/s
D. 96kb/s
[单项选择]在E1载波中，每个子信道的数据速率是 (16) ，E1载波的控制开销占 (17) 。
A. 32kbps
B. 64kbps
C. 72kbps
D. 96kbps
[判断题]高频振荡的正弦波信号可作为携带信息的载波。信息传输时，利用信源信号去调整载波的某个参数，这个过程称为解调。
[单项选择]The Environmental Protection Agency unveiled a detailed proposal Wednesday for using the government’s regulatory powers to curb greenhouse gas emissions—reassuring foreign allies of the U.S. commitment to fight climate change and warning Congress that the administration will act on its own if lawmakers fail to address the issue. The rules would force new or substantially modified industrial plants emitting at least 25,000 tons of greenhouse gases a year to employ "best available control technologies and energy-efficiency measures" to minimize emissions.
The agency unveiled its proposal hours after Senate Democrats introduced their version of the global warming bill that passed the House in June, and as international climate negotiators gathered in Bangkok, Thailand, to prepare for global warming treaty talks in Copenhagen in December. The EPA and Senate actions stoked(激起 ) optimism among environmentalists and others. Some had voiced concern that reaching agreement in Copenhagen
A. It is beneficial to our health to reduce emissions.
B. It triggers new technology for developing economy.
C. It will never put a burden on the business again.
D. It protects our environment to have a better futur
[填空题]到1990年，NSFNET的第二个主干网的速率已经提高到T1载波，T1载波的传输速率是（）。
