单项选择题
A.under heavy loads
B.during hot gas defrost
C.under light loads
D.during starting conditions
单项选择题 Which of the following problems could cause air to blow out through the inlet air filter of a running compressor?（）
单项选择题 In which of the listed hydraulic systems will the installation of an oil cooler be necessary?（）
单项选择题 Which of the following problems would be the probable cause for the faulty operation of a reciprocating air compressor suction valve?（）