Vegetations are most common on A: the tricuspid valves B: the pulmonary valves C: the mitral and aortic valves D: the right atrial appendage

The period when both inlet valves and exhaust valves are open is referred to as （）.

Overload protection on hydraulic system is provided by the use of （）. A: stop valves B: pressure relief valves C: balance valves D: regulating speed valve

The starting air system usually has （） to prevent starting if anything is not in order. A: stop valves B: interlocks C: non-return valves D: air vent

The purpose of the safety relief valves installed on an auxiliary boiler is to （）.

What is the purpose of the intake/exhaust valves in a diesel engine? （）

The camshaft is used to open and close the valves with the motion of the pistons.

Fuel injection valves should be taken out， cleaned， and lifting checked every （）.

In structure, all hydraulic control valves consist of______ , ______ (spool, cone or ball) and ______ used to control the valve core.

Temperature control valves installed in the jacket cooling water system of a diesel engine modulates the rate of water flow through the （）.