Answer:
A partir de los 10 o 15 días
Nos is the answer.
There you go.
Reduce the number of trips you take in your car.
Reduce or eliminate fireplace and wood stove use.
Avoid burning leaves, trash, and other materials.
Avoid using gas-powered lawn and garden equipment.
It's C. In fact it's <em>more </em>popular in the Spanish speaking world than in the United States. Hope this helps!