pneumatically placed concrete

例句：

1. 1. The valve is pneumatically sealed to prevent leaks.
   阀门是气密密封的，以防止泄漏。
2. 2. The airbagwas designed to provide a pneumatically sealed environment forthe passengers.
   空气囊被设计为为乘客提供气密密封的环境。
3. 3. The sealant was applied pneumaticallyto ensure a tight fit.
   密封剂被气密地应用以确保紧密配合。