13 new pages in Concepts: don't miss the useful ones

Stuck on Concepts? We added 13 fresh pages so students can revise without hunting across the site.

New in this section:

• Summary of the Chapter (In a Nutshell)
• Concept Map — Chapter 3
• 3.5.1 Treatment of Diseases
• 3.5 How to Prevent and Control Diseases?
• and 9 more fresh pages

Open it while it is fresh. Share it with someone revising the same chapter.