他清除了鞋中的一粒石子。

He removed a stone from his shoe.

《柯林斯英汉双解大词典》

她弯下腰，把鞋里的一粒石子抖出来。

She bent down to shake a pebble out of her shoe.

《牛津词典》

这些冰和小岩石粒的松散集合形成了彗星。

Loose collections of these ices and small rocky particles form into comets.

youdao

If you take one of those individual grains of sodium chloride, look at it carefully, you will see the edges look like this.

如果你拿起,氯化钠晶体的一粒，仔细观察，你可以看到这样的棱角。

麻省理工公开课 - 固态化学导论课程节选

So this validates de Broglie and it also validates the whole concept of wave-particle duality.

这就证实了德布罗意的观点,也证实了,波粒二象性的原理。

麻省理工公开课 - 固态化学导论课程节选

Or you could ask the question, I have this restriction enzyme, at what regions on this plasmid will it cut?

你也可以这样问,我的这种限制性内切酶,会从质粒的哪个区域切开呢

耶鲁公开课 - 生物医学工程探索课程节选