Most of its members are the students and teachers of the thirtyone colleges.
它的大部分成员是31所学院的学生和教师。
2
There are about thirty-one million blacks in the U.S.
美国大约有三千一百万黑人。
《柯林斯英汉双解大词典》
3
In America, people are faced with more and more decisions every day, whether it's picking one of thirty-one ice cream flavors, or deciding whether and when to get married.