Sigma.
[医] 千分之一秒
🗣️ 情景例句
No, you needn't do that.
不行呀，你不必这样。
My brother used to speak French to me all the time.
我的兄弟过去总是对我说法语。
But people who are cut off not only from foreign tourists, but even from their own countrymen can be hostile to travellers.
但是，那些不但与外国旅游者隔绝，而且与本国同胞隔绝的人们有可能对游客抱有敌意。