Sigma bond
[化] σ键
🧩 词语组成解析
[计] 求和\\n[医] σ(希腊文第十八个字母)
🗣️ 情景例句
It was so kind of them.
他们太客气了。
You'd better go and see a doctor about that.
关于那个毛病，你最好去看医生。
If I had been, I would not have been able to get home for lunch. '
如果真戴着它，我现在就不能回家来吃午饭了。”