Multiple choice

Layers of which of the following substances are present in the filtration chamber?

  1. Sand and gravel

  2. Gravel and charcoal

  3. Sand, gravel and charcoal

  4. Charcoal and sand

  5. Only charcoal

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Layers of sand, gravel and charcoal are present in the filtration chamber.