cannon primer

例句：

1. 1.The cannon was fired to signal the attack.
   大炮被发射以发出攻击的信号。
2. 2.The cannon primer was a crucial part of the weapon's operation.
   大炮的引信是武器操作中至关重要的部分。
3. 3.The cannon primer was designed to ensure the smooth functioning of the cannon.
   大炮的引信设计用来确保大炮的顺利运作。