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distinction
似た鳥の見分けに慣れてきた。
I'm getting used to telling apart similar-looking birds.
双子の見分けがつかないほど似ていた。
The twins looked so alike that I couldn't tell them apart.
毒キノコと食用キノコの見分けは専門家でも難しい。
Telling apart poisonous and edible mushrooms is difficult even for experts.