Cfc, freon, and aerosols are becoming less commonly used because they
a) cause acid rain.
b) harm the ozone layer.
c) have radioactive waste.
d) cause alzheimer's disease.

Answer : The correct option is, (B) Harm the ozone layer.

Explanation :

CFC and Freon are used as refrigerant gases and as propellants in aerosol sprays. And the aerosols is a suspension of fine liquid or solid particles in the gas.

When CFC, Freon, and aerosols reaches to the stratosphere region, the UV light affects them and they release chlorine atoms. And the chlorine atoms break down the ozone molecules and harm the ozone layer. The ozone layer is useful to us because it protect us from the U.V rays which are the harmful rays.

Hence, CFC, Freon, and aerosols are becoming less commonly used because the harm the ozone layer.

la última respuesta, tanto a   y c.

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.