There are about thirty-one million blacks in the U.S.

美国大约有三千一百万黑人。

Twenty-six and five make thirty-one.

二十六加五，三十一。

All the rest has thirty-one except February alone.

除了二月自己，剩下的月份都有三十一天。

All the rest have thirty-one except February alone.

除了二月其余的有三十一天。

You can look at page thirty-one in the Hughes edition.

你们可以看到休斯版本的31页。