dead point的用法和樣例：
例句
- These gateways provide a choke point at which security and auditing can be imposed.
這些關卡提供了一個扼止點，在此可以進行安全檢查和審計。 - The spark is therefore timed to occur before the piston reaches top dead center, otherwise maximum pressure would not be reached in time.
因而，在活塞到達上死點前，火花便會發生，否則就不可能適時達到最高的壓力。
