1.But an unexpected fact was noted: certain minerals( pitchblende, chalcolite, autunite) had a greater activity than might be expected on the basis of their uranium or thorium content.
2.We found that pitchblende contains at least two radioactive materials, one of which, accompanying bismuth, has been given the name polonium, while the other, paired with barium, has been called radium.
14.He tested a piece of pitchblende, the principal ore of uranium, and found it to be seven hundred million years old—very much older than the age most people were prepared to grant the earth.
他测试了一块青铀矿, 发现它有七亿年的历史 - - 比大多数人准备给予地球的年龄要大得多。机翻
「A Short History of Nearly Everything」评价该例句:好评差评指正