Answer: Heat\pressure control
Explanation: In order to create metamorphic rock, it is vital that the existing rock remain solid and not melt. If there is too much heat or pressure, the rock will melt and become magma.
Answer: B. A secondary pollutant
An acid rain is an example of a secondary pollutant because it is a chemical reaction of two gases namely, the sulfur dioxide and the nitrogen dioxide. The acid rain is not also directly emitted by the atmosphere.
The answer is the last option
A pedigree chart shows the occurrence and/or appearance of phenotypes of a particular gene or organism and its ancestors from one generation
