Hb
abbr. [军] 厚膛壁身管（Heavy Barrel）
📖 牛津释义
HB
abbr
缩写 = (of lead used in pencils) hard black (ie medium hard) （指铅笔芯）硬黑（即硬度适中）
an HB pencil 一支HB的铅笔. Cf 参看 B, H.
🗣️ 情景例句
Thanks for asking.
谢谢你的邀请。
I've got nothing to lose.
我豁出去了！
One hour and seventeen minutes passed and we had not even covered half the distance.
1小时17分过去了，走了还不到一半路程。