Since the clean air act was passed in 1970, why is the air still not clean?

Cause of the people in the world polluting and not obeying laws, its true there are some people trying to solve it, but the amount of people that are making it worse out numbers it.

Because the factories we have put chemicals in the air and when we drive cars, those help pollute the air with the gasoline. And not to mention Greenhouse gases as well those are within our atmosphere as well. So basically everything you have that was most likely made by a factory or a car you might have or something that has chemicals that get into the air around you is what makes the air unclean

Neurotransmitters are messengers responsible for communication between neurons. they are released from synaptic vesicles and are received by receptors.  the communication is referred to as neurotransmission. the following statement is true about neurotransmitters: a. they're stored in synaptic vesicles in the axon.