Poliovirus
[医] 脊髓灰质炎病毒
🗣️ 情景例句
If you don't know a person's last name, use 'ma'am' or 'sir'.
如果你不知道一人的姓， 你应称呼他为 'ma'am' 或 'sir' 。
I asked him to play with me, but he wouldn't.
我请他和我玩，但是他不肯。
gradually, and often quite swiftly,
那么渐渐地，往往也是很顺利地，