Bb
abbr. 滚珠轴承（ball bearing）；铅笔芯（double black）
🗣️ 情景例句
What was your graduation thesis on?
你毕业论文是什么题目？
My book has a dark blue cover.
我的书有一个深蓝色的封面。
I really can't agree with you. I prefer science.
我真的不能同意你的看法。我更喜欢自然科学。