bachelor

他四十岁了还单身，是个快乐的单身汉。

He's forty and still a happy ___bachelor.

他获得了北京大学经济学学士学位。

He received a ___bachelor’s degree in economics from Peking University.

年轻的独身海豹在繁殖季节会聚集在岩石上。

Young ___bachelor seals gather on the rocks during mating season.