单项选择题
A.holding the discharge valve open
B.relieving the intercooler pressure to the atmosphere
C.using an enlarged, permanently opened clearance expansion space
D.a pre-charged accumulator
单项选择题 Machinery driving fuel oil transfer and fuel oil service pumps must be fitted with a remote means of stopping the machinery from （）.
单项选择题 If an electric motor driven air compressor fails to start, it may be due to a （）.
单项选择题 Which of the following precautions should always be carried out in dry dock?（）