At the age of thirty-one, Florence went to Germany and learned all about nursing.
三十一岁时,弗洛伦斯去了德国,学习了所有关于护理的知识。
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.