4 sentences

1. 五行学说认为水克火。

   wǔ​xíng xué​shuō rèn​wéi shuǐ kè huǒ.

   The theory of the Five Elements holds that Water overcomes Fire.

   Source: Dong Chinese Dictionary

2. 儒家学说强调理化万民的重要性。

   Rú​jiā xué​shuō qiáng​diào lǐ​huà wàn​mín de zhòng​yào​xìng.

   Confucianism emphasizes the importance of civilizing and educating the masses.

   Source: Dong Chinese Dictionary

3. 弗洛伊德提出了著名的精神分析学说。

   Fú​luò​yī​dé tí​chū le zhù​míng de jīng​shén fēn​xī xué​shuō.

   Freud proposed the famous theory of psychoanalysis.

   Source: Dong Chinese Dictionary

4. 达尔文的进化论是生物学中最著名的学说之一。

   Dá'ěr​wén de jìn​huà​lùn shì shēng​wù​xué zhōng zuì zhù​míng de xué​shuō zhī​yī.

   Darwin's theory of evolution is one of the most famous theories in biology.

   Source: Dong Chinese Dictionary