/ˈspeʃ.ə.laɪz/
~ (in sth) to become an expert in a particular area of work, study or business; to spend more time on one area of work, etc. than on others 专门研究（或从事）；专攻
Many students prefer not to specialize too soon.
很多学生不愿过早地确定专业。
He specialized in criminal law.
他专攻刑法。
The shop specializes in hand-made chocolates.
这家商店专营手工制作的巧克力。