然而气门达到全开位置需要一定时间，完全关闭也需要一定时间。

However, it takes some time for the valve to open to its full position. It also takes time for it to close tightly.

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但是像进气门一样，排气门需要时间到达充分打开和关闭的位置。

But like the inlet valve, the exhaust valve needs time to reach the full-open position, it also needs time to reach the full-closed position.

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