EXCLAM
（书面语中用于表示在交谈时作出回应或引起他人注意或表示惊讶、失望）啊
Ah is used in writing to represent a noise that people make in conversation, for example to acknowledge or draw attention to something, or to express surprise or disappointment.
例句
I'm meeting Anna Langenbach. Ah, this seems to be the train now...
我要去见安娜·朗根巴赫。啊，这像是我要乘坐的火车了。
Ah, so many questions, so little time.
啊，这么多问题，这么短的时间。