2 sentences for 主体 (zhǔ​tǐ)

1. 学生应该是学习过程中的主体。

   xué​sheng yīng​gāi shì xué​xí guò​chéng zhōng de zhǔ​tǐ.

   Students should be the main subjects of the learning process.

   Source: Dong Chinese Dictionary

2. 这座建筑的主体结构已经完工了。

   zhè zuò jiàn​zhù de zhǔ​tǐ jié​gòu yǐ​jīng wán​gōng le.

   The main structure of this building has been completed.

   Source: Dong Chinese Dictionary