Some rocks from volcanoes break down to form black sand.

有些火山岩被撞碎后会形成黑色的沙。

youdao

When these rocks break down into the grains that make up the sand on our beaches, their colour is mostly determined by the presence or absence of iron.

当岩石分解成为颗粒够成沙滩时，颜色则是由铁元素氧化物的存在与否决定的。

youdao

They tried to break the icy sand with their knives, but it was not easy.

他们试图用他们的刀，打破在冰冷的沙滩，但这并不容易。

youdao

More than 10 drillers have already received Department of Environmental Protection permission to use mine discharges for fracking, a technique in which millions of gallons of water, along with chemical additives and sand, are pumped down a well to break apart gas-bearing shale deposits.

WSJ: Pa. pushes drillers to frack with coal mine water