3 sentences

1. 恺撒在公元前44年被刺杀。

   Kǎi​sā zài gōng​yuán qián44 nián bèi cì​shā.

   Caesar was assassinated in 44 BC.

   Source: Dong Chinese Dictionary

2. 这一历史事件发生在公元五世纪。

   zhè yī lì​shǐ shì​jiàn fā​shēng zài gōng​yuán wǔ shì​jì.

   This historical event took place in the fifth century AD.

   Source: Dong Chinese Dictionary

3. 秦始皇于公元前221年统一了中国。

   Qín Shǐ​huáng yú gōng​yuán qián221 nián tǒng​yī le Zhōng​guó.

   Qin Shi Huang unified China in 221 BC.

   Source: Dong Chinese Dictionary