center 指三维空间的中心点，也可比喻抽象事物的中心。
middle 一般指时间、空间或过程两端间等距的部分。
heart 指事物最内部或最重要的部分，表地理位置时可与center换用。
core 指某事物固定的中心部分或最重要的核心部分。比喻意义指某物的精华。
midst 书面语用词，指在一个群体的深处或在某活动的进程中。
参考例句
1. These two questions are the core of the paper. 这两个问题就是该论文的核心所在。
2. How do enterprises in Yunnan form core competition? 云南企业如何构建核心竞争能力？
3. Proof responsibility is the key and core of proof system. 证明责任是证据制度的核心和关键所在。
英英解释
n.
1. the center of an object
2. a small group of indispensable persons or things
3. the central part of the Earth
4. the choicest or most essential or most vital part of some idea or experience
5. a cylindrical sample of soil or rock obtained with a hollow drill
6. an organization founded by James Leonard Farmer in 1942 to work for racial equality
7. the central meaning or theme of a speech or literary work
8. the chamber of a nuclear reactor containing the fissile material where the reaction takes place
9. a bar of magnetic material (as soft iron) that passes through a coil and serves to increase the indu v.
1. remove the core or center from
