Air pollution is caused by many things. Great clouds
of smoke come from factories. Cars send smoke and fumes into the air. Burning
waste fills the air with bits of dirt. Even burning leaves add smoke to the air.
Sometimes, planes cannot find their landing spots through smoke. Smoke of all
kinds is bad to breathe and can do great harm to the body.
Still, we cannot live without air. We must find a way to clean the air we
have. In time, we may have factories that are run by atomic
energy. Our cars may run on smoke-free electric power. Scientists are also
working on new ways to help the oil burned by cars from making fumes. Waste may
be burned in the sand on ocean floors. These changes might keep
our air clean in the years to come. But until then, many scientists are looking
for ways to make air cleaner now. Why would electric cars cut down on air pollution
A. They go only a short way.
B. They are easier to keep clean.
C. Electric power has no smoke.
D. Electric cars need no energy.