Bb
abbr. 滚珠轴承（ball bearing）；铅笔芯（double black）
🗣️ 情景例句
He is a tremendous walker.
他很能走路。
I had never seen a grown man break down and cry.
我从未曾看到过一个这么强壮的汉子痛哭失声。
That's a great idea!
好主意！