放射性同位素

例句：

1. 1. Radioactive isotopes are used in medical imaging to detect tumors.
   放射性同位素在医学成像中用于检测肿瘤。
2. 2. The scientist discovered a new isotope of carbon, which could be used for energy production.
   科学家发现了一种新的碳同位素，可用于能源生产。
3. 3. The study focused on the properties of radioactive isotopes and their applications in various fields.
   该研究专注于放射性同位素的性质及其在各个领域的应用。