Using a hollow tube, they drill into the tree and extract a 5-mm wide cylinder that shows each ring starting with the most recent, just under the bark.

VOA: standard.2010.04.05

And the poem goes on, and this is the tone of a poem. It's a poem of crisis, a poem of a kind of hollow speaker, someone who emerges as, more or less, buried alive. And this is supposed to reflect both personal crisis and a historical crisis.

然后这首诗继续娓娓道来，这就是诗歌的韵律,这是首关于危机的诗，关于一个有点言之无物的叙述者,最后活活烧死的诗，这恰好反映了,个人和历史的危机。

耶鲁公开课 - 1945年后的美国小说课程节选

You have a tube, a transparent--a tube--a hollow tube, and at the top of the tube you throw a ball through so it whips through the tube and it comes out.

用一根管子,一根透明中空的管子,从管子最上面,你丢进去一个小球,小球迅速穿过管子,飞出来

耶鲁公开课 - 心理学导论课程节选