单项选择题
The quantity of cooled air delivered by an air conditioning unit should （） the sum of the quantity of air re-circulated to the unit and the quantity mechanically exhausted.
A.balance B.not balance C.be more than D.be less than
单项选择题 The shutter of the evaporator was blocked with （）, it means there was too much evaporation.
单项选择题 The inner part of the condenser should be cleaned with （）.
单项选择题 In the cargo winch, spur reduction gearing transfers the motor drive to （）.
