例句與造句

1. That tube was evacuated by the highly effective mercury vacuum pump created by Hermann Sprengel.
2. Little more was done with this phenomenon until 1856 when German glassblower Heinrich Geissler created a mercury vacuum pump that evacuated a glass tube to an extent not previously possible.
3. By the 1870s, Crookes ( among other researchers ) was able to evacuate his tubes to a lower pressure, 10  " 6 to 5x10  " 8 atm, using an improved Sprengel mercury vacuum pump invented by his coworker Charles A . Gimingham.
4. It's difficult to find mercury vacuum pump in a sentence. 用mercury vacuum pump造句挺難的