单项选择题
A.bilge water may enter the exhaust pipe
B.entry of air may cause vapor lock
C.carbon monoxide may enter the interior of the vessel
D.the joint gaskets may be blown
单项选择题 The connected joints of pipe，usually made of three joints of pipe approximately 90 feet long，racked in the derrick when making a trip are called a（）.
单项选择题 The C02 flooding system is actuated by a sequence of steps which are（）.
单项选择题 The bypass valve on a self-contained breathing device should be opened if（）.