Answer: B. Valves
The intake valve allows oxygen laden air to be drawn into the cylinder. The air mixes with the fuel and combusts in the cylinder to deliver power.
The exhaust valve opens to expel combustion products before the next cycle begins.
<h3>Another positive benefit of civil service is that it can provide the workforce with a predictable and easy to understand set of criteria for advancement. In many cases it clearly spells out the specific criteria needed in order to move upward (“through rank”) in the workforce.</h3>