You see, companies used to drill for oil by going straight down.

你瞧，过去石油公司常常采用垂直钻探。

youdao

You see, oil deposits can stretch for miles - but when a drill went straight down, the well was only tapping oil from the immediate vicinity.

你瞧，石油储备区可能延绵数英里，但是当钻头直接垂直钻入时，油井只会利用到邻接区域的石油。

youdao

You see, companies used to drill for oil by going straight down.

你瞧，过去石油公司常常采用垂直钻探石油。

youdao

It's not really hard. You just make your bed neat, remember to stand up straight, and always answer every question with "Yes, Drill Sergeant."

VOA: standard.other

In all three spots, you could drill straight through and come up in a place where you might bump into the occasional seal and, in one place if you arrive at the right time of year, a scientist or two.

NPR: Dig a Hole to China? Try a Sandwich Instead

So if you are a packaged product fan and prefer ETFs to straight bonds, then you need to drill down into the ETF holdings.

FORBES: Juicy and Junky High Yield ETFs