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
No. Please endorse the check at the back.
不会的，请在支票背面签名。
Many a fine dish has nothing on it.
虚有其表。
Once there was an old tiger.
从前有一只年迈的老虎。