单项选择题
The（） is a smaller valve fitted in the auxiliary steam supply line, and is usually of the non-return type.
A.main stem stop valve B.auxiliary steam stop valve C.feed check or control valve D.blow down valve
单项选择题 The（）is fitted in the main steam supply line and is usually of the non-return type.
单项选择题 The lifting pressure of （） is set in the presence of a Surveyor it is locked and cannot be changed.
单项选择题 The propeller is pushed on to the tubeshaft taper and made tight by（）
