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單項(xiàng)選擇題

In extreme weather conditions, either hot or cold, control of the air conditioning plant presents （） difficulties.

A.few
B.little
C.a little
D.less

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單項(xiàng)選擇題

Because of the reduced （）in the distillation system, some of the sea water boils as it flows through the tubes of the evaporator.

A.pressure
B.temperature
C.density
D.volume

單項(xiàng)選擇題

Because of the reduced （） in the distillation system, some of the sea water boils as it flows through the tubes of the evaporator.

A.pressure
B.temperature
C.density
D.volume