3 sentences

1. 他在论文中详细考证了冯字在古籍里的词义。

   tā zài lùn​wén zhōng xiáng​xì kǎo​zhèng le Féng zì zài gǔ​jí lǐ de cí​yì.

   In his thesis, he conducted detailed textual research on the meaning of the character 'Feng' in ancient texts.

   Source: Dong Chinese Dictionary

2. 史学家对这段文字的真实性进行了严密的考证。

   shǐ​xué​jiā duì zhè duàn wén​zì de zhēn​shí​xìng jìn​xíng le yán​mì de kǎo​zhèng.

   Historians have conducted rigorous textual research on the authenticity of this passage.

   Source: Dong Chinese Dictionary

3. 他最近正忙着考证，希望能拿到会计师资格。

   tā zuì​jìn zhèng máng zhe kǎo​zhèng, xī​wàng néng ná​dào kuài​jì​shī zī​gé.

   He's been busy studying for certificates recently, hoping to get his accounting qualification.

   Source: Dong Chinese Dictionary