B-b
abbr. 滚珠轴承（ball bearing）；铅笔芯（double black）
🗣️ 情景例句
How many days will it take for my mail to reach its destination?
我的信件到达目的地要用几天？
He that regards not a penny,will lavish a pound.
小钱不知节省，大钱将滥花。
Watch out!
当心。