Answer:
C
Explanation:
Many kinds of air pollution can't be seen, which means A is incorrect. Any kind of pollution can be harmful to you, which means B is incorrect too. Air pollution is very harmful but in most cases can't be directly seen, so C is correct. Pollution can be found everywhere, so D is incorrect also.
Answer:
(look at the explanation below)
Explanation:
A condition caused by mutations in one or more genes is called a genetic disorder. In some cases, gene mutations are so severe that they prevent an embryo from surviving until birth. These changes occur in genes that are essential for development, and often disrupt the development of an embryo in its earliest stages.
The answer is D. Always true in all places
Answer an unit of measurement.
For example: inch, hour, minutes, feet, meters.
