2 sentences

1. 既然犯了错，理所当然应该承担后果。

   jì​rán fàn le cuò, lǐ​suǒ​dāng​rán yīng​gāi chéng​dān hòu​guǒ.

   Since a mistake was made, it's only natural to bear the consequences.

   Source: Dong Chinese Dictionary

2. 他付出了努力，获得成功是理所当然的。

   tā fù​chū le nǔ​lì, huò​dé chéng​gōng shì lǐ​suǒ​dāng​rán de.

   He worked hard, so it is only natural that he succeeded.

   Source: Dong Chinese Dictionary