1. 空位;空缺;空白
    If someone or something creates a vacuum, they leave a place or position which then needs to be filled by another person or thing.

    e.g. The collapse of the army left a vacuum in the area...
           这支军队的溃败使这个地区出现了军事真空。
    e.g. His presence should fill the power vacuum which has been developing over the past few days.
           他的出现将填补过去这几天形成的权力真空。

2. 在封闭状态中;与外界隔绝
    If something is done in a vacuum, it is not affected by any outside influences or information.

    e.g. Moral values cannot be taught in a vacuum...
           道德价值观的教育不能脱离实际。
    e.g. We lived in a vacuum — no life, no news, no books.
           我们生活在与世隔绝的环境里——没有其他生物，收不到外界消息，也没有书看。

3. 用真空吸尘器打扫
    If you vacuum something, you clean it using a vacuum cleaner.

    e.g. I vacuumed the carpets today...
           今天我用吸尘器清洁了地毯。
    e.g. It's important to vacuum regularly.
           定期用吸尘器吸尘很重要。

4. 真空
    A vacuum is a space that contains no air or other gas.

    e.g. Wind is a current of air caused by a vacuum caused by hot air rising...
           风是由于热空气上升产生真空导致的一种气流运动。
    e.g. The spinning turbine creates a vacuum.
           旋转的涡轮形成了一块真空区域。