例句與造句

1. The interior of the tube must be kept a hard vacuum to preserve the photo cathode .
   顯象管內(nèi)部一定要保證高真空才能保護光電陰極。
2. In may , the team ran tests at lower temperatures but with harder vacuums as oxygen could be extracted with less power under this condition
   研究小組在五月曾嘗試在低溫但高度真空的環(huán)境下進(jìn)行實驗，因為在這環(huán)境下，提取氧氣所需的能量會較少。
3. It's difficult to find hard vacuum in a sentence. 用hard vacuum造句挺難的