This lowers the temperature. This makes the flames smaller. This absorbs the burning substance. This keeps oxygen from reaching the fire.
I gave my students this multiple choice question: Why can a small fire be put out by placing a heavy blanket over it?

Only one answer is correct among these 4 choices:
- This lowers the temperature.
- This makes the flames smaller.
- This absorbs the burning substance.
- This keeps oxygen from reaching the fire.

Could you tell me which one is correct?

This keeps oxygen from reaching the fire.