2 sentences for 主攻 (zhǔ​gōng — specialize)

1. 她主攻京剧中的青衣行当。

   tā zhǔ​gōng Jīng​jù zhōng de qīng​yī háng​dang.

   She specializes in the 'Qingyi' role in Peking Opera.

   Source: Dong Chinese Dictionary

2. 他在读研期间主攻软件工程，尤其擅长开发手机应用。

   tā zài dú​yán qī​jiān zhǔ​gōng ruǎn​jiàn gōng​chéng, yóu​qí shàn​cháng kāi​fā shǒu​jī yìng​yòng.

   During his graduate studies, he specialized in software engineering and was particularly good at developing mobile applications.

   Source: Dong Chinese Dictionary