Sigma
[计] 求和\\n[医] σ(希腊文第十八个字母)
🗣️ 情景例句
I would like to mail this package.
我想把这包裹给寄了。
It seems he's a millionaire.
看起来他好像是百万富翁。
because this is easier to shape than other kinds.
因为燧石较之其他石头更容易成形。