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搜题
【单选题】
某电视台曝光了某地养殖鸡场违规使用抗生素和激素来养殖鸡肉,使鸡能够在 40 天长到 5 斤,有关专家指出,食用此类鸡会导致人体免疫力不断下降,这个现象反映了市场调节的缺陷是 ( )A.
盲目性
B.
滞后性
C.
竞争性
D.
自发性
拍照语音搜题，微信中搜索"皮皮学"使用
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举一反三
【单选题】The input stage of an integrated operational amplifier is generally composed of ( ) .
A.
differential amplifier circuit
B.
voltage amplifier circuit
C.
power amplifier circuit
D.
current source
【单选题】Most amplifiers can be classified in by their function. If the output signal is larger in voltage amplitude than the input signal, the amplifier is a( ). If there is no voltage gain, but the output p...
A.
voltage amplifier
B.
power amplifier
C.
transistor amplifier
D.
operational amplifier
【单选题】A transistor amplifier has an input signal applied to its emitter terminal and an output signal taken from its collector terminal. The amplifier is a(n) ( ).
A.
common-emitter amplifier
B.
common-base amplifier
C.
common-collector amplifier
D.
emitter follower
【单选题】Amplifier ac input and output currents are ( ).
A.
always 180°s out of phase
B.
180° out of phase in all but one amplifier configuration
C.
in phase in all but one amplifier configuration
D.
always in phase
【单选题】If the amplifier is optimized to amplify current signals, it is called ( )
A.
current amplifier
B.
a voltage amplifier
C.
a power amplifier
D.
an operational amplifier
【多选题】Most amplifiers can be classitied in by their function. If the output signal is larger in voltage amplitude than the input signal ,the amplifier is a (). if there is no voltage gain , , but the outpu...
A.
voltage amplifier
B.
power amplifier
C.
transistor amplifier
D.
operational amplifier
【多选题】Most amplifiers can be classified in by their function. If the output signal is larger in voltage amplitude than the input signal, the amplifier is a( ). If there is no voltagegain, but the output pow...
A.
voltage amplifier
B.
power amplifier
C.
transistor amplifier
D.
operational amplifier
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