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單項(xiàng)選擇題

For the intermediate condition, thermostats must be correctly set （）.

A.by trial and error
B.by and large
C.automatically
D.very easily

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單項(xiàng)選擇題

Most air conditioning units have （） for adjusting the ratio of recirculated fresh airCare must be taken not to reduce the fresh air so that stuffiness or smells arise.

A.catch plates
B.dampers
C.regulating valves
D.fans

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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