某放大电路在负载开路时,测得输出电压为5V,在输入电压不变的情况下接入3KΩ的负载电阻,输出电压下降到3V,说明该放大电路的输出电阻为()
A. 5KΩ
B. 4KΩ
C. 2KΩ
D. 3KΩ
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听力材料中记数字时,要写出全部字母,例如:two thousand()
There was a_increase in the number of private cars in China from 2013 to 2016()
A. stiff
B. stricken
C. stolen
D. stable
The pie chart above__ an expenditure structure of the residents during the Spring Festival in a Chinese city()
A. presents
B. misleads
C. reveals
D. shows
At least three primary_account for such changes()
A. contributors
B. tractors
C. spectators
D. factors