1. Such anomalies are due to the relative abundance of the "isotopes" or varieties of each element. 这种反常现象是由于同位素比较丰富或者各个元素比较多样化。
2. The isotopes of a given element have the same chemical properties but slightly different physical properties. 一个特定元素的同位素具有相同的化学特征，但在物理性质上有一些细微差异。
3. Most hydrogen and oxygen atoms in water are stable, but traces of both elements are also present as heavier isotopes. 在水中大多数氢原子和氧原子是稳定的，但这两个元素也有微量以较重的同位素形式存在。
4. She had often carried test tubes containing radioactive isotopes in her pocket, remarking on the pretty blue-green light they gave off. 她经常把装有放射性同位素的试管放在口袋里，对试管里发出的漂亮的蓝绿光赞不绝口。
5. By measuring the proportion of heavier hydrogen and oxygen isotopes along a strand of hair, scientists can construct a geographic timeline. 通过测量一束头发上较重的氢和氧同位素的比例，科学家可以构建一个地理时间轴。
