guard aperture

例句：

1. 1. The engineer carefully guarded the aperture to prevent any accidental discharge.
   工程师小心地守护着炮口，以防任何意外的泄漏。
2. 2.The scientist used a special device to guard the aperture during the experiment.
   科学家使用一种特殊的设备来保护炮口进行实验。
3. 3.The missile was launched with great force, but the aperture was well-protected by the shielding material.
   导弹发射时力量巨大，但炮口被防护材料很好地保护起来。