更多"The British used radio waves becaus"的相关试题:
[单项选择]The British used radio waves because they______.
A. were more exact than sound waves
B. could not be discovered
C. could pass through fog and clouds
D. were easier to use than sound waves
[单项选择]If the radio waves had reached our planet one hundred years before, we would have______.
A. sent an immediate answer
B. sent an alarm against extraterrestrial attack
C. sent a short reply
D. sent no answer
[单项选择]The practical use of radio waves brought about______.
A. new machines for planes
B. a radio directing and ranging device
C. new radio sets for RAF bombers
D. a discovering device
[单项选择]Radio signals are waves that are used to _________ music or speech.
A. transfer
B. transmit
C. transport
D. transform
[单项选择]
Because noises modulate radio frequency, radio stations use a band of frequencies to prevent interference with other stations.（）
A. govern
B. adapt
C. temper
D. renovate
[单项选择]Because noises modulate radiofrequency, radio stations use a band of frequencies to prevent interference with other stations.（）
A. govern
B. adapt
C. temper
D. renovate
[单项选择]Sound waves reflected from a hill can be used to calculate the______.
A. Speed of sound
B. time between a sound and ifs echo
C. height of the hill
D. distance of the hill
[单项选择]Sound waves reflected from a hill can be used to estimate ____________.
A. height of the hill
B. speed of sound
C. distance of the hill
D. intensity of sound
[单项选择]Because of its intimacy,radio is usually more that just a medium;it is_____.
A. firm
B. company
C. corporation
D. enterprise
[单项选择]Because of its intimacy, radio is usually more than just a medium; it is ______.
A. firm
B. company
C. corporation
D. enterprise
