Multiple choice

The rock which is used for rubbing one's legs is

  1. granite

  2. pumice

  3. obsidian

  4. conglomerate

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

It is pumice. Pumice is a stone which has many holes and pockets which are formed by the gases trapped inside at the time of its formation. It is light and hence, is used for rubbing one's legs.