Metals expand when they are heated.

金属受热会膨胀。

Zinc is used to protect other metals from corrosion.

锌被用来保护其他金属免受腐蚀。

Low temperature contracts metals.

低温使金属收缩。

Lead is one of the softer metals.

铅是硬度较低的金属之一。

The metals can be reused.

金属可以被重复利用。

Tungsten is classified among the metals.

钨归入金属类。

Iron and some nickel, both of which are metals.

铁和一些镍，它们俩都是金属。

Electronic wastes also contain many poisonous metals.

电子垃圾也会含有很多有毒金属物。

There were few natural resources, no timber, stone, or metals.

那里几乎没有什么自然资源，也没有木材、石头或金属。

Metals are opaque, so the other electrode must be transparent.

金属是不透明的，因此另一个电极必须是透明的。

Electronic devices contain valuable metals such as gold and silver.

电子设备含有贵重金属，如金和银。

Electronic products contain valuable metals that could be recovered.

电子产品内含有价值的可回收金属。

This is partly driven by the rising price of raw materials and metals.

这在一定程度上是受原材料和金属价格上涨的推动。

In order to be purified, or combined into alloys, metals must be melted.

为了净化或合成合金，金属必须熔化。

Together, the value of these metals is estimated to be about $52 billion.

这些金属的总价值估计约为520亿美元。

They and colleagues have invented a way for damaged metals to heal themselves.

他们与同事研发出了一种能让受损金属自我愈合的方法。

The value of the metals, like gold and silver in the waste around the world, is amazing.

像世界各地废料中的金银这类金属，价值惊人。

Scientists have strived to find a solution by mixing it with expensive metals such as nickel.

科学家们一直在努力寻找一种解决方案，将其与镍等昂贵金属混合使用。

They can thrive in soil with high concentrations of metals that are toxic to most other plants.

它们能在含有对大多数其他植物有毒的高浓度金属的土壤中茁壮成长。

These asteroids are like the terrestrial planets, in that they're composed mostly of rocky material and metals.

这些小行星像类地行星一样，主要由岩石物质和金属构成。

Engineers like ceramics because they can be heated without melting, unlike metals and plastics, though, they are brittle.

工程师们喜欢陶瓷，因为陶瓷在加热时不会熔化，但与金属和塑料不同的是，陶瓷易碎。

The terrestrial planets—like Mars and Earth—composed largely of rocks and metals, and the large gas giants, like Jupiter.

诸如火星和地球这样的类地行星主要由岩石和金属构成，而木星则是大型气态行星。

It would have been relatively easy for a person with knowledge of metals to melt down bronze objects and forge them into coins.

对懂金属的人来说，熔化青铜制品并将其锻造成硬币是相对容易的。

The market for recycled commodities like aluminum and other metals remains strong despite economic changes in the recycling industry.

尽管回收行业发生了经济变化，但铝和其他金属等回收商品的市场依然强劲。

Charles Boutron is an expert on the impact of heavy metals on the environment at the National Center for Scientific Research in France.

查尔斯·布特隆是法国国家科学研究中心的一名专家，研究重金属对环境影响。

The process is possible only with certain materials (plastics, resins and metals) and with a precision of around a tenth of a millimeter.

这个过程只能用特定的材料（塑料，树脂和金属），精度在0.1毫米左右。

We are talking about the Neolithic period here, which was the time before stone tools began to be replaced by tools made of bronze and other metals.

我们这里在说的是新石器时代，是石器开始被青铜和其他金属制工具所取代之前的那个时代。

Trading was important, as so many raw materials, the semiprecious stones for the decoration of the temples, timbers for roofs, and all metals, had to be imported.

由于大量原材料，如用于装饰庙宇的半宝石石料、建造屋顶的木材和所有金属都需要进口，贸易变得至关重要。

Agronomists studying the herb have discovered that it produces large amounts of histidine, an amino acid that, in test-tube solutions, renders these metals chemically inert.

研究这种药草的农学家发现，它会产生大量的组氨酸，这种氨基酸在试管溶液中会使这些金属具有化学惰性。