Multiple choice

______________________ is made up of bits of rock, minerals, and a lot of humus.

  1. bedrock

  2. subsoil

  3. bedsoil

  4. topsoil

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

Topsoil is the uppermost layer of soil, which contains the highest concentration of organic matter (humus) and microorganisms, making it vital for plant life.