theory

noun

1. 学说；论；说
   a formal set of ideas that is intended to explain why sth happens or exists
   1. According to the theory of relativity, nothing can travel faster than light.
      根据相对论，任何东西都无法超越光速。
2. 理论；原理；原则
   the principles on which a particular subject is based
   1. the theory and practice of language teaching
      语言教学理论与实践
3. （未证明的）意见；看法；推测
   an opinion or idea that sb believes is true but that is not proved
   1. I have this theory that most people prefer being at work to being at home.
      依我看，多数人喜欢工作而不愿待在家里。

1. N-VAR 理论;学说
   A theory is a formal idea or set of ideas that is intended to explain something.
   1. Marx produced a new theory about historical change based upon conflict between competing groups...
      马克思创立了一种新理论，认为历史的演变是基于对立集团之间的冲突之上的。
   2. Einstein formulated the Theory of Relativity in 1905.
      爱因斯坦于 1905 年创立了相对论。
2. N-COUNT 观点;见解
   If you have a theory about something, you have your own opinion about it which you cannot prove but which you think is true.
   1. There was a theory that he wanted to marry her...
      有人认为他想娶她。
   2. My theory about divorce is that it's not the split-up that damages children, it's how it is handled.
      我对离婚的看法是，伤害孩子的不是婚姻的破裂，而是处理离婚的方式。
3. N-UNCOUNT (实践科目、技能的)理论基础
   The theory of a practical subject or skill is the set of rules and principles that form the basis of it.
   1. He taught us music theory.
      他教我们乐理。
   2. ...graduates who are well-trained in both the theory and practice of statistics.
      在统计学理论和实践两方面都训练有素的毕业生
4. PHRASE 从理论上说;照理说
   You use in theory to say that although something is supposed to be true or to happen in the way stated, it may not in fact be true or happen in that way.
   1. A school dental service exists in theory, but in practice, there are few dentists to work in them.
      照理说，学校也有牙医诊所，可实际上，里面的牙医寥寥无几。

1. They have learned the lessons of business management theory, and put them into action.
   他们不仅学习了商业管理理论方面的课程，并且学以致用。
2. It's only a theory, admittedly, but the pieces fit together
   诚然，这只是一种理论，但各部分互相吻合。
3. Students learned the practical application of the theory they had learned in the classroom
   学生们学会了将课堂上学到的理论付诸实际应用。
4. Radio signals received from the galaxy's centre back up the black hole theory
   从该星系中心收到的无线电信号证实了黑洞理论。
5. The idea that software is capable of any task is broadly true in theory.
   认为软件能够处理任何任务的观念从理论上说基本是正确的。
6. In theory I'm on call day and night.
   从理论上说，我现在昼夜待命。
7. Einstein had the chutzpah to discard common sense and long-established theory.
   爱因斯坦敢于抛弃常识和长期公认的理论。
8. This theory is widely derided by conventional scientists.
   这一理论遭到了守旧派科学家的普遍嘲笑。
9. This theory has now been discounted.
   这个理论被打了折扣。
10. To date there is no evidence to support this theory.
    到目前为止，还没有证据支持这种理论。
11. These courses provide the groundwork of statistical theory.
    这些课程介绍的是统计学理论的基础。
12. No further illumination can be had from this theory.
    这一理论不能给人以更深刻的启迪。
13. One theory is that the infection has been present in humans for a very long time
    有一种理论认为，这种传染病存在于人类中已经有很长时间了。
14. Zoologist Eugene Morton has propounded a general theory of the vocal sounds that animals make.
    动物学家尤金·莫顿提出了一个有关动物发声的概括性理论。
15. Much of her work is speculative, based on psychoanalytic theory rather than empirical data.
    她的著作中有相当一部分内容是推测性的，建立在精神分析理论之上而缺乏来自实际经验的数据。
16. Both quantum mechanics and chaos theory suggest a world constantly in flux.
    量子力学和混沌理论都表明世界永远处于不断变化中。
17. This theory bears no relation to reality.
    这个理论和现实没什么联系。
18. The next step is to put the theory into practice
    下一步是要将理论付诸实践。
19. Marx produced a new theory about historical change based upon conflict between competing groups
    马克思创立了一种新理论，认为历史的演变是基于对立集团之间的冲突之上的。
20. There was a theory that he wanted to marry her
    有人认为他想娶她。
21. My theory about divorce is that it's not the split-up that damages children, it's how it is handled.
    我对离婚的看法是，伤害孩子的不是婚姻的破裂，而是处理离婚的方式。
22. He taught us music theory.
    他教我们乐理。
23. A school dental service exists in theory, but in practice, there are few dentists to work in them.
    照理说，学校也有牙医诊所，可实际上，里面的牙医寥寥无几。
24. The doctrine of surplus value is the cornerstone of Marx's economic theory.
    剩余价值学说是马克思经济理论的基石。
25. Einstein's theory of relativity won for him universal esteem.
    爱因斯坦的相对论赢得了全世界对他的崇敬。
26. My theory is established on the solid basis of facts.
    我的理论是以可靠的事实作为根据的。
27. He has established his theory.
    他确立了他的学说。
28. His new theory has caused a sensation throughout the civilized world.
    他的新理论轰动了整个文明世界。
29. In this way they can better apply theory to practice.
    这样他们就能更好地把理论运用到实践中去。

n.

in theory

• 理论上；按理说
  used to say that a particular statement is supposed to be true but may in fact be wrong
  1. In theory, these machines should last for ten years or more.
     从理论上讲，这些机器应能用十年以上。
  2. That sounds fine in theory, but have you really thought it through?
     这话听起来很有道理，但是你真正全面考虑过没有？

noun

1. a tentative insight into the natural world
   1. a scientific hypothesis that survives experimental testing becomes a scientific theory
   2. he proposed a fresh theory of alkalis that later was accepted in chemical practices

   Synonym:    hypothesispossibility

2. a belief that can guide behavior
   1. the architect has a theory that more is less
   2. they killed him on the theory that dead men tell no tales

3. a well-substantiated explanation of some aspect of the natural world
   1. theories can incorporate facts and laws and tested hypotheses
   2. true in fact and theory