thirty[ˈθɜ:ti]的y发/i/音。
He lived in Canada in the thirties.
三十年代他住在加拿大。By sunset we had covered thirty miles.
到日落时我们已走了三十英里。
Some thirty people attended the funeral.
大约有三十人参加了葬礼。
She thinks nothing of walking thirty miles a day.
她认为一天步行三十英里不足为奇。
She's in her mid-thirties—thirty-six to be exact.
她三十五岁左右—确切地说是三十六岁。
