通信英语强化训练试题(一)
Ⅰ 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, occupying
C. 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, locate
C. 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, choosing
C. 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, when
C. 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 identify
C. specified, identified
D. 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 call
C. 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 receive
C. transmitting, receiving
D. 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, used
C. find, use
D. be found, using
( )10.
Traditionally ,
the idle state _________the mark level. By convention this
corresponds _________a logical 1 level.
1