A thermos flask consists of two very thin walls of glass with a vacuum between them, which means that the air and everything else has been extracted.

 
  • 熱水瓶是由兩層很薄的玻璃構成的。在兩層玻璃壁之間是一個(gè)真空。所謂真空是指在兩層玻璃壁之間的空氣以及其他一切東西都抽掉了。
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