2 sentences

1. 这是历史上最严寒的一个冬天。

   zhè shì lì​shǐ​shàng zuì yán​hán de yī gè dōng​tiān.

   This is the coldest winter on record.

   Source: Dong Chinese Dictionary

2. 夏启是中国历史上第一个王朝的开创者。

   Xià Qǐ shì Zhōng​guó lì​shǐ​shàng dì​yī​gè wáng​cháo de kāi​chuàng zhě.

   Xia Qi was the founder of the first dynasty in Chinese history.

   Source: Dong Chinese Dictionary