perfect vacuum

• 绝对真空

perfect vacuum的用法和样例：

例句

1. The food is kept in the absolute vacuum.
   这食物保存在绝对真空中。
2. In contrast to the mechanism of conduction and convection,radiation may take place in a perfect vacuum.
   与传导和对流的原理不同，辐射可在完全真空中进行。