(1) and (2)
(1) only
(2) only
(1),(2) and (3)
第1题：
第2题：
the inlet valve is open
the exhaust valve is open
both valves are closed
both valves are open
第3题：
The globe valve has a bulbous body, housing a valve seat and screw down plug or disc arranged at right angles to the axis of the pipeAccording to the above sentence, which of the following statements is not true?
A.The profile of the valve is like a globe
B.The valve seat is set into the bulbous body
C.The plug or disc of the valve is made vertical to the axis of the pipe
D.The valve seat is located at right side of the plug or disc
第4题：
Holding the valve open for a long period
Increasing the starting air pressure used
Opening the stating air valve quickly
Reducing the starting air valve size
第5题：
the direct acting relief valve is used for controlling lower flows and pressure
the pilot operated relief valve is used for controlling higher flows and pressure
the pilot operated relief valve is used for controlling lower flows and pressure
the controlling accuracy of direct acting relief valve is worse than that of the pilot operated relief valve
第6题：
the inlet valve is open
the exhaust valve is open
both valves are close
both valves are open
第7题：
Worn intake valve guides
Pitted pre-combustion chambers
Loose valve tappets
High exhaust back pressure
第8题：
High cylinder firing pressure, accompanied by low exhaust temperature, can result from ___.
A.improper fuel rack positing
B.lengthy exhaust valve duration
C.extend operation at light load
D.excessively early injection timing
第9题：
Return-flow
Uniflow
Cross-flow
Direct flow
第10题：
Loss of compression for that cylinder
Misfiring or rough running
Damage to the valve
All of the above