4 sentences

1. 每条河流都有它的源头。

   měi tiáo hé​liú dōu yǒu tā de yuán​tóu.

   Every river has its source.

   Source: OpenSubtitles

2. 我们要从源头解决问题。

   wǒ​men yào cóng yuán​tóu jiě​jué wèn​tí.

   We need to solve the problem at its source.

   Source: Dong Chinese Dictionary

3. 我们必须找到源头。

   wǒ​men bì​xū zhǎo​dào yuán​tóu.

   We have to find the source.

   Source: OpenSubtitles

4. 我们应当建立健全管理制度，从源头上杜绝浪费现象。

   wǒ​men yīng​dāng jiàn​lì jiàn​quán guǎn​lǐ zhì​dù, cóng yuán​tóu shàng dù jué làng​fèi xiàn​xiàng.

   We should establish a sound management system to eliminate waste at its source.

   Source: Dong Chinese Dictionary