2H
词形变化
2Hs
复数
2Hs
释义与例句
n.
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1.
A grade of pencil with lead that makes lighter marks than a pencil grade H but darker marks than a pencil of grade 3H; a pencil with hard lead.
不可数 -
2.
A pencil of grade 2H.
不可数 -
3.
Alternative form of ²H (“hydrogen-2”)
不可数