单项选择题
A.main engines B.main boilers C.pipes and fittings D.A and B
A （）, sometimes called filters, is a device designed to...
单项选择题A （）, sometimes called filters, is a device designed to prevent the passage of unwanted solids into the system.
A.steam trap B.check valve C.separator D.strainer
To maintain the down stream pressure within defined lim...
单项选择题To maintain the down stream pressure within defined limits over a range of flow and despite any changes in supply pressure, （） is fitted.
A.a check valve B.a gate valve C.a pressure reducing valve D.a quick closing valve
The main objective of the SOLAS Convention is to specif...
单项选择题The main objective of the SOLAS Convention is to specify （） for the construction, equipment and operation of ships, compatible their safety.
A.at most references B.at least references C.maximum standards D.minimum standards
