clean air is an example of which no one can be excluded from and benefits all citizens.

Answer;

-Public goods

​Clean air is an example of public goods, which no one can be excluded from and benefits all citizens.

Explanation;

A public good is a product that one individual can consume without reducing its availability to another individual, and from which no one is excluded. These goods are both non-excludable and non-rivalrous in that individuals cannot be effectively excluded from use and where use by one individual does not reduce availability to others.

-Public goods (and services) include economic statistics and other information, law enforcement, national defense, parks, defense, public fireworks, lighthouses, clean air and other environmental goods among other things for the use and benefit of all.

the answer is true.  i do believe this is the answer because of the amount of wrecks people get into each year.  if you double this with avoiding those so said wrecks, that would make you a "skilled" driver.

answer; sales of books;