theory
英['θɪərɪ]
美['θiəri]
- n. 理论；原理；学说；推测
词组搭配
in theory
used in describing what is supposed to happen or be possible, usually with the implication that it does not in fact happen
理论上（应该）；照道理
in theory, things can only get better; in practice, they may well become a lot worse.
理论上情况只会变好，实际上却很可能变得更糟。