Miners tread down into the crater to collect blocks of bright-yellow sulfur, which forms when gaseous and molten sulfur emerges from fumaroles -- volcanic vents -- and hardens.

从火山口喷发出的硫磺蒸汽硬化凝结后，就形成了那些闪着黄色亮光的硫磺岩块，矿工们小心翼翼的探到火山坑底，冒着生命危险搜集这些黄色亮块。

youdao

After cutting an eight day losing streak on Wednesday, the Dow Jones Industrial Average tread down again, shedding 238 points to 11, 658 by 10:56 AM.

FORBES: Initial Claims Show An Economy Still In Limbo As Equities Break Down

In that kind of circumstance, I think the natural political instinct is to tread lightly, keep your head down, and to play it safe.

WHITEHOUSE: President Obama Takes Questions from Senate Democrats