5 sentences

1. 他的物理理论非常深奥。

   tā de wù​lǐ lǐ​lùn fēi​cháng shēn'ào.

   His physics theories are very profound.

   Source: Dong Chinese Dictionary

2. 这其中的道理非常深奥，还需细讨。

   zhè qí​zhōng de dào​li fēi​cháng shēn'ào, hái xū xì​tǎo.

   The logic behind this is very profound and requires further study.

   Source: Dong Chinese Dictionary

3. 他的理论非常深奥，普通人很难理解。

   tā de lǐ​lùn fēi​cháng shēn'ào, pǔ​tōng​rén hěn nán lǐ​jiě.

   His theories are very profound and difficult for ordinary people to understand.

   Source: Dong Chinese Dictionary

4. 这本书深奥难懂，我花了一周才卒读。

   zhè běn shū shēn'ào nán dǒng, wǒ huā le yī zhōu cái zú dú.

   This book is so profound and difficult that it took me a week to finish reading it.

   Source: Dong Chinese Dictionary

5. 他已经连续三个晚上在啃那本深奥的物理书了。

   tā yǐ​jīng lián​xù sān gè wǎn​shang zài kěn nà běn shēn'ào de wù​lǐ shū le.

   He has been poring over that profound physics book for three consecutive nights.

   Source: Dong Chinese Dictionary