The resistance of some trees to disease can be traced to____.

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• The resistance of a conductor varies （）

  A . directly as its length and inversely as its cross-sectional area B . inversely as its length and directly as its cross-sectional area C . directly as its length and directly as its cross-sectional area D . inversely as its length and inversely as its cross-sectional area

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• When the voltage remains constant and the resistance is increased in a series circuit, the flow of current （）

  A . increases by the square of the original value B . increases C . remains the same D . decrease

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• The resistance of electric wire will decrease as its （）

  A . length increases B . cross-sectional area increases C . temperature increases D . percent of metallic purities increase

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• （）is a function of the reactive / resistive characteristics of the load items and cannot be adjusted by manipulating the alternator control devices.

  A . Power factor B . Power ratio C . compression ratio D . Compression factor

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• The deck beam brackets of a transversely framed vessel resist（）.

  A . hogging stresses B . sagging stresses C . racking stresses D . shearing stresse

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• Each cylinder is closed at the top by a （）, made of a special heat-resistant steel.

  A . cylinder liner B . coupling flange C . cylinder cover D . piston crow

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• Which of the following statements concerning a simple parallel resistance circuit is correct?（）

  A . The voltage drop across each resistor is the same B . The total current flow equals the reciprocal of the sum of the individual currents C . The total resistance equals the sum of the individual resistances D . The total voltage equals the sum of the individual voltages across each resistance

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• The total resistance of a parallel circuit is always （）.

  A . larger than the greatest branch resistance B . smaller than the lowest branch resistance C . equal to the sum of the individual branch resistances D . one-half the sum of the individual branch resistance

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• Which of the following statements is true concerning simple parallel resistance circuits?（）

  A . The total current flow equals the sum of the individual currents B . The total current flow equals the reciprocal of the sum of the individual currents C . The total resistance equals the sum of the individual resistance D . The total voltage equals the sum of the individual voltages across each resistance

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• The resistance to the movement of the globule in oily water mixture depends on its size and the （） of the fluid.

  A . pressure B . velocity C . gravity D . viscosity

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• Some large A-Cmotors are equipped with heatersThese could be （） (1)resistance heaters bolted directly to the frame (2)low voltage windings embedded in the motor windings

  A . (1) only B . (2) only C . either (1) or (2) D . neither (1) or (2)

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• The unit of electrical resistance is the （）

  A . ampere B . volt C . watt D . ohm

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• In the piping systems of a vessel，what type of valve gives the least resistance to fluid flow when fully open?（）.

  A . Globe valve B . Butterfly valve C . Gate valve D . Packless valve

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• The pipe friction and the resistance will （） as a result of an increase in the amount of fluid flowing through the system.

  A . reduce B . rise C . raise D . fall

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• "Cast iron has poor corrosion resistance to sea water, especially in the presence of bronzes" Implies（）.

  A . east iron is a cheap material B . cast iron can pollute sea water C . cast iron has mere corrosive than bronzes to sea water D . cast iron is more corrosive to sea water when it meets with bronze

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• The purpose of treating the cooling water of the diesel engine is to（） Ⅰ. resist the scale formation in the cooling chamber Ⅱ.lubricate the engine part Ⅲ.increase thermal capacity Ⅳ.resist corrosion

  A . Ⅰ+Ⅱ B . Ⅱ+Ⅲ C . Ⅲ+Ⅳ D . Ⅰ+Ⅳ

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• The reason for the market decline of the milk drink is the consumers' resistance to sugar-free milk drink.

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• Which of the following types of power is most likely to generate followers’ resistance?_____

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• deals with the War of Anti-Japanese Resistance and civil disputes between many warring Chinese groups.

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• The Chinese People's War of Resistance Against Japan played a great role in the international anti-Fascist war.

  A．Y B．N C．NG

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• Only one－fifth of the Americans meet the guidelines for both aerobic and resistance_______.

  A．A.exercise B．B.exercises C．C.exercising D．D.to exercise

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• Which of the following statements is true concerning simple parallel resistance circuits？

  A.The total current flow equals the sum of the individual currents B.The total current flow equals the reciprocal of the sum of the individual currents C.The total resistance equals the sum of the individual resistance D.The total voltage equals the sum of the individual voltages across each resistance

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• 【单选题】Sentence idioms can be divided into（） 答案:Hardly can I resist the temptation of her.

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• The total resistance of a parallel circuit is always______.

  A.larger than the greatest branch resistance B.smaller than the lowest branch resistance C.equal to the sum of the individual branch resistances D.one-half the sum of the individual branch resistances

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