dichotomy (二分法)

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Definition

1 : a division into two especially mutually exclusive or contradictory groups or entities

//the dichotomy between theory and practice

also : the process or practice of making such a division

//dichotomy of the population into two opposed classes

2 : something with seemingly contradictory qualities

//it's a dichotomy, this opulent Ritz-style luxury in a place that fronts on a boat harbor

— Jean T. Barrett

3 : the phase of the moon or an inferior planet in which half its disk appears illuminated

4a : BIFURCATION

especially : repeated bifurcation (as of a plant's stem)

b : a system of branching in which the main axis forks repeatedly into two branches

c : branching of an ancestral line into two equal diverging branches

資訊來源：

M-W.com

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