We did this using a galvanized (zinc-plated) tub, a stew pot with a copper bottom, and a bottle of lemon juice.

我们使用镀锌的盆、铜底的炖锅和一瓶柠檬汁来实现。

youdao

What do you think will happen if we take the copper-bottom pot out of the tub and use a single penny instead?

如果我们将铜底锅从盆中取出而使用一个硬币代替，您认为会发生什么情况？

youdao

We face a tough six to eight months, but towards the end of the year we should touch bottom on copper, aluminum and zinc.

CNN: Money & Investing

After World War II Lowe's became known hundreds of miles around for rock-bottom prices on nails, copper pipe and lumber by the railcar-load.

FORBES: Merchant Princes

Both byproduct metals have risen in price since the second quarter of 2009 (copper has gained 25% and zinc 19%.) Stronger copper and zinc prices will reduce cash cost per ounce and go directly toward the bottom line for companies with significant byproduct credits, like Barrick Gold, Newmont Mining, Goldcorp, Agnico-Eagle and Yamana Gold.

FORBES: Magazine Article