A4
n. A4型纸（规格为297×210毫米的纸）
🗣️ 情景例句
He is quick-witted.
他反应灵敏。
I can't seem to get to sleep.
我好象睡不着。
While the battered car was moving away, Roy stopped his bus and telephoned the police.
当那辆被撞坏的车开走后，罗伊停下车，给警察挂了电话。