通信英语强化训练试题（一） 单项选择题：(Choose the best one)( )1. Furthermore, we shall prove that a minimum theoretical sampling frequency of order 6. 8 kHz is required _a voice channel _the range 300Hz to 3. 4 kHz.A. convey, occupy B. to convey, occupyingC. conveying, occupied D. convey, to occupy( )2. For example, the signal _from a satellite, _in far outer space, is very weak.A. received, located B. receive, locateC. receiving, locating D. to receive, to locate( )3. If we consider binary transmission, the complete information about a particular message will always _by simply _the presence or absence of the pulse.A. obtain, detect B. be obtained, detecting C. obtained, detected D. obtaining, detected( )4. 4. There is an inherent advantage for _noisy environments by _digital transmission.A. overcoming, choose B. overcome, choosingC. overcome, choose D. overcoming, choosing( )5. Each voice channel has a separate coder，the unit _converts sampled amplitude values to a set of pulses; And decoder, the unit _performs the reverse operation.A. who, who B. when, whenC. where, where D. that, that( )6. The problem is easily overcome by _a frame format, where at the start of each frame a unique sequence of pulses is placed _the start of the frame.A. specify, identify B. specifying, so as to identifyC. specified, identifiedD. specify, identifying( )7. An asynchronous serial data link is said _character oriented，as information is transmitted in the form of groups of bits _characters.A. be，calling B. to being，to callC. been，call D. to be，called( )8. This interface is so called because the _data and the _data are not synchronized over any extended period.A. transmit，receive B. to transmit，to receiveC. transmitting，receivingD. transmitted，received( )9. Serial data transmission systems _in the telephone，Morse code, and even the smoke signals once _by native Americans.A. are finding，using B. are found，usedC. find, useD. be found, using( )10. Traditionally，the idle state _the mark level. By convention this corresponds _a logical 1 level.A. is referred to, asB. is referred as, inC, is referred to as, toD. is referred，within( )11. The transmitter then sends the character，1 bit at a time，by _each successive bit on the line for a duration of T seconds, _all bits have been transmitted.A. place, stillB. placed，sinceC. placing, untilD. placing，because( )12. When the data link connects a CRT terminal _a computer，_problems arise, as the terminal is itself character oriented.A. into, manyB. on，a fewC. in, a fewD. to，few( )13. _the receiving end of a synchronous serial data link，the receiver continually monitors the line _a start bit.A. On，lookingB. Within，look forC. In, look atD. At，looking for( )14. As companies realized they could save money and gain productivity by _networking technology, they added networks and expanded _networks almost as rapidly as new network technologies and products could be introduced.A. use, existB. using, existingC. to use, to existD. used, existed( )15. The OSI reference model allows you _the network functions that occur at each layer. More importantly, the OSI reference model is a framework you can use _how information travels throughout a network.A. view, understandB. viewing, understandingC. viewed, understoodD. to view, to understand( )16. The transport layer segments data from the _hosts system and reassembles the data into a data stream on the _hosts system.A. sending, receivingB. to send, to receiveC. sent, receivedD. send, receive( )17. The data link layer provides the transit of data _a physical link. In so doing, the data link layer is concerned _physical addressing, network topology, network media access, and error detection.A. with, acrossB. at, inC. between, inD. across, with 短语英译汉：(Translate the following phrases into Chinese)1. the schemes for performing these three functions 2. a series of amplitude values 3. a speech channel of telephone quality 4. a sequence of 8-binary digits 5. a minimum theoretical sampling frequency 6. a voice channel occupying the range 300 Hz to 3. 4 kHz 7. 8-digits per sa