1．30的英语：thirty，英 [ˈθɜːti] 美 [ˈθɜːrti]。
2．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。
3．At thirty years old, he was already earning £ 40 000 a year. 他三十岁时已拿到4万英镑的年薪了。
