核子

例句：

1. 1. The nucleus ofthe planet is located in its core.
   行星的核心位于其中心。
2. 2. The scientists are studyingthe nucleus of the atom.
   科学家们正在研究原子的核心。
3. 3. Thenucleus of theEarth is made up of ironand nickel.
   地球的核心由铁和镍组成。