单项选择题
The air compressor pumps air to the （）.
A.expansion tank B.combustion chamber C.air receiver D.evaporator
单项选择题 The air compressor pumps air to the （）.
单项选择题 The （） stage air compressors are widely used on board the ship.
单项选择题 The air filter is fixed in the （） of an air compressor.
