constituent 常可与component换用，指某一整体不可少的部分或成分。
element 指一个整体必不可少或固有的部分，强调一个复杂整体中最基本、最简单的元件、元素或成分等。
ingredient 普通用词，含义笼统。既可指混在一起而本身没有变化的物质，如配料，又可指与别的物质混在一起，发生了变化的成分。
element的英语例句：
1. In order to make it safe, the element is electrically insulated.
为安全起见，该元件作了电绝缘处理。
2. There is an element of exhibitionism in the parents' performance too.
那对父母的表现也显得有些爱出风头。
3. With its unique heating element it makes perfect coffee.
其独特的电热元件使它能够煮出非常美味的咖啡。
4. You will probably notice an element of quirkiness in his behaviour.
你可能会发现他的行为有点怪异。
5. The chronological sequence gives the book an element of structure.
时间顺序让这本书有了一定的结构。
6. European political union would be incomplete without a defence element.
如果没有防御体系，欧洲政治联盟就不完整。
7. The criticisms have at least an element of truth and validity.
那些批评至少有一丝真实性和合理性。
8. His testimony was an important element of the Prosecution case.
他的证词是这宗公诉案件中的一个重要因素。
9. They have started showing a strong soul element in their sound.
他们的音乐风格开始表现出一种强烈的灵乐特色。
10. There is a strong element of truth to each of these explanations.
这些解释每一个都很有道理。
11. My stepmother was in her element, organizing everything.
我的继母得心应手地料理着一切。
12. Cost was a key element in our decision.
价钱是我们决策时考虑的主要因素。
13. Any investment involves an element of risk.
任何投资都有一定的风险。
14. Carbon is an element, while carbon dioxide is a compound.
碳是一种(化学)元素, 而二氧化碳则是一种化合物.
15. I am out of my element when people start talking about music.
人们一谈论起音乐我就感到茫然。