num.第三十一
At thirty, he signed on as first mate with a cargo ship. 他30岁时受雇于一艘货船当了大副。
He's been drinking whiskey on the sly for thirty years. 他暗中偷喝威士忌酒已有三十年了。
The students in our class number thirty. 我班总共有三十名学生。
The hotel has garage space for thirty cars. 这家饭店有停放30辆小汽车的车位。
There are more than thirty footmen in this hotel. 这家旅馆里有三十多名仆役。
