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treble range (in Japanese music); high note
「甲」 has other readings with different meanings.
契約書の甲は売主、乙は買主を指す。
In the contract, Party A refers to the seller and Party B to the buyer.
契約書の甲と乙は、それぞれ当事者を指します。
I used 甲.
試験の成績は甲乙つけがたいほど接戦でした。
甲 was important.