单项选择题
A.slightly opened
B.throttled
C.fully opened
D.halfway opened
单项选择题 The capacity of a centrifugal pump can be increased by the installation of a larger diameter impeller Another means of increasing the pump capacity is to ().
单项选择题 Which of the following forms of energy is demonstrated through the process of combustion?()
单项选择题 While inspecting the steering system at sea, you should check for ().