Drop several seeds over the surface of the pot and cover with a thin layer of vermiculite, a substance that can hold air, water and nutrients.

VOA: special.2009.04.21

Things are not "made up" in Frost, "not made up" in the sense of imagined, called up out of thin air, like fairies and elves.

弗罗斯特的诗歌里没有编造，没有想象，像仙女和精灵那样的凭空想象。

耶鲁公开课 - 现代诗歌课程节选

At about nineteen-thousand meters, the air is so thin and the amount of oxygen so small that a person needs a lot of special equipment to survive.

VOA: special.2011.04.06

The first is the lack of oxygen in the extremely thin air.

VOA: special.2010.06.30

The air grew thin within a day.

VOA: special.2010.07.31

The best known is "Into Thin Air."

VOA: special.2010.06.30