1、The nuclei of most atoms consist of protons and neutrons.
大多数原子的核心由质子和中子组成。

2、The cell's nucleus controls all of its activities.
细胞的细胞核控制着所有的活动。

3、The city center is the nucleus of economic and cultural development.
城市中心是经济和文化发展的核心。

4、Scientists are studying the behavior of atomic nuclei.
科学家正在研究原子核的行为。