In English, "补充" can be translated to "supplement." The word comes from the Latin word "supplementum," which means "something added or completed." Here are some example sentences and their translations in Chinese:

I'm taking a daily supplement to help improve my health. (我每天都在服用一种保健品来提高我的健康水平。)

The teacher gave us a supplement to the textbook to help us better understand the material. (老师给了我们一份教科书的补充材料，帮助我们更好地理解这些材料。)

The new wing of the museum will be a supplement to the existing exhibits. (博物馆的新馆区将是现有展览的补充。)