30的英文是：thirty.
了解：
She thinks nothing of walking thirty miles a day.
她认为一天步行三十英里不足为奇。
By sunset we had covered thirty miles.
到日落时我们已走了三十英里。
相关介绍
only thirty students graduated in Chinese last year.
去年只有三十名学生获得汉语学士学位。
The driver was a trim young woman of perhaps thirty.
驾车者是一位大约三十来岁的苗条年轻女子。
If I might hazard a guess , I'd say she was about thirty.
让我来猜的话，我说她大约三十岁。
Yesterday no fewer than thirty climbers reached the summit.
昨天不少于三十名登山者到达了顶峰。
The Tornado was about thirty feet from Mace's right wingtip.
“龙卷风”离“梅斯”的右机翼尖约三十英尺。
