whew
(also phew), interj (used as the written form of any of various sounds made by breathing out strongly or whistling to express amazement, relief, exhaustion or dismay 用作有声响的呼气声或口哨声之书面语象声词, 表示惊讶、 宽慰、 疲劳或沮丧均可)
Whew! That car was going fast! 嘿! 那辆汽车可真快!
Whew! That was a lucky escape! 哇! 这可是侥幸脱险哪!