1. [单选题]When deciding the composition of the engineering watch, which may include____ appropriately, many factors shall be taken into account.
A. satisfied engineers
B. qualified ratings
C. satisfied chief engineer
D. qualified chief' engineer
2. [单选题]In the refrigeration system, a shortage of refrigerant is indicated by
A. the compressor short cycling on high pressure cut out switch
B. high suction pressure
C. high head pressure
D. bubbles in the sight glass
