When the engine is shut off, the intake manifold cools and a slight vacuum forms as a result .

这是因为当发动机熄火时，进气歧管冷却而产生轻微的真空。

youdao

One does not inhale the smoke, but if one gets very good at it, one does not even have to puff: the slight vacuum created in the mouth by nose breathing will draw the finest of puffs through the stem.

不需要将烟吸入，但若有人精于此道，都不必再次吸：鼻孔呼吸时在口腔内造成的小小的真空就足以将那缕轻烟吸回烟嘴。

youdao

The detection systemcould not press or squeeze the egg like the graders did, but what would happenif they could pull on the egg with a slight negative pressure, or vacuum?

检测系统不能像分级员一样按压或挤压鸡蛋。 然而，如果它们能够用极小的负压或真空把鸡蛋牵引起来，结果会怎样呢？

youdao