1、30的英语：thirty，英 [?θ??ti] 美 [?θ??rti]。
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。
4、We are expecting thirty or so people to come. 我们预计要来三十人左右。