3 sentences

1. 学习外语需要持之以恒。

   xué​xí wài​yǔ xū​yào chí​zhī​yǐ​héng.

   Learning a foreign language requires perseverance.

   Source: Dong Chinese Dictionary

2. 成功的关键在于持之以恒的努力。

   chéng​gōng de guān​jiàn zài​yú chí​zhī​yǐ​héng de nǔ​lì.

   The key to success lies in persistent effort.

   Source: Dong Chinese Dictionary

3. 无论做什么事，都必须有持之以恒的精神。

   wú​lùn zuò shén​me shì, dōu bì​xū yǒu chí​zhī​yǐ​héng de jīng​shén.

   No matter what you do, you must have the spirit of perseverance.

   Source: Dong Chinese Dictionary