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- Polonium is a naturally radioactive metallic element. 钋是一种具有天然辐射性的金属元素。
- In 1932 the Joliot-Curies made a radioactive metal bombard beryllium--which is a non-radio-active metal--with its rays. The result was that the beryllium, too, became radioactive- even more so than the original source of the rays. 1932年，约里奥一居里夫妇用一种放射性金属射线轰炸非放射性金属的铍元素，结果铍元素也具有了放射性，而且其放射性比原来放射性金属所发出的射线还要强。
- Radioactive ray is material thing. 放射线是实际的物质。
- I do not know why acids eat in metals. 我不知道酸腐蚀金属的原因。
- Radium and uranium are radioactive elements. 镭和铀是放射性元素。
- Copper and gold are both metals. 铜和金都是金属。
- Metals undergo expansion when heated. 金属加热时会膨胀。
- It follows that acids eat in metals. 由此可知，各种酸对金属都有腐蚀作用。
- A certain discharge of possible radioactive effluent. 一定量的可能有放射性的废水。
- Memory has been shown to reside in some metals. 已经证实，记忆存在于某些金属中。
- Metals expand when they are heated. 金属遇热则膨胀。
- She knows why the metal is the good conductor. 她知道金属为什么是好的导体。
- Some metals weld better than others. 有些金属容易焊，有的不容易焊。
- Metals contract in cold weather. 金属在寒冷的天气里收缩。
- Certain metals are attracted to a magnet. 某些金属会受磁石的吸引。
- A radioactive isotope of carbon, especially carbon 14. 放射性碳碳的一种放射性同位素，尤指碳14。
- Metals contract as they get cooler. 金属遇冷则收缩。
- Can I fasten these metal plates with rivets? 我可以用铆钉把这些金属板固定在一起吗？
- The acid eats into metals quickly. 酸腐蚀金属很快。
- A naturally occurring or artificially produced radioactive element. 放射性元素自然产生或人为制造的放射性元素
