A4
n. A4型纸（规格为297×210毫米的纸）
🗣️ 情景例句
Tomorrow is another day.
有明天就有希望。
Pitchers have ears.
隔墙有耳。
Man-made satellites have been sent up into space by many countries.
许多国家都成功地把人造卫星送入了太空。