您要查找的是不是：
- Some pumps and all vacuum cleaners work by suction. 有些泵和所有真空吸尘器都是借吸力工作的。
- His wife's death left him a vacuum in his life. 他妻子的去世使他的生活变得空虚。
- This is a room with good ventilation. 这是个通风良好的房间。
- Her husband's death left a vacuum in her life. 她丈夫的死使她的生活变得空虚。
- Some people are living in a vacuum. 有些人过着与世隔绝的生活。
- A vacuum cleaner is a handy household tool. 吸尘器是一种使用方便的家庭用具。
- The shop repairs vacuum cleaners. 这家店修理吸尘器。
- The porter turned off the vacuum. 清洁工关掉真空吸尘器。
- The symbol for the speed of light in a vacuum. 表示真空中光速的物理符号
- Sealed under low pressure or a partial vacuum. 抽空密封的在低压或部分真空状态下密封起来的
- vacuum ventilation system 真空通风系统,真空式通风系统
- vacuum ventilation [医] 真空通风(抽出式机械通风)
- Dirt and dust are drawn into a vacuum cleaner by suction. 污物和灰尘被吸入吸尘器。
- We could not pull apart two plates which enclosed a vacuum. 如果两个盘子间是真空，我们就无法将它们分开。
- The ventilation is poor, the lieutenant admits. 中尉承认，通风设备很糟糕。
- Workers should be allowed full ventilation of all their difficulties. 工人们应被允许公开讨论他们所有的困难。
- Operating by means of suction or by maintaining a partial vacuum. 抽真空的用吸取的方式或用维持部分真空的方式来运作的
- They altered the house to improve its ventilation. 他们把房子改装一下使它更通气。
- Regeneration production of ventilation fan. 换气扇的换代产品。
- Open the window for some ventilation. 打开窗子好通风。
