自2010年至今的四级考试中， 共出现过 次
自2010年至今的六级考试中， 共出现过 次
N-VAR 理论;学说 A theory is a formal idea or set of ideas that is intended to explain something.
Marx produced a new theory about historical change based upon conflict between competing groups...
Einstein formulated the Theory of Relativity in 1905.
爱因斯坦于 1905 年创立了相对论。
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.
There was a theory that he wanted to marry her...
My theory about divorce is that it's not the split-up that damages children, it's how it is handled.
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.
He taught us music theory.
...graduates who are well-trained in both the theory and practice of statistics.
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.
A school dental service exists in theory, but in practice, there are few dentists to work in them.