thirty-one
01
三十一
the number 31; the number of days in January, March, May, July, August, October, and December
例子
She bought thirty-one books at the sale.
她在促销中买了三十一本书。
He turned thirty-one last week and had a small celebration.
上周他满三十一岁，并举行了一个小型的庆祝活动。
