What is the most important reason to control the conditions of an experiment? O to make the experiment easier to repeat
O to reduce the amount of data that must be recorded
O because this is necessary for graphing the data
O because this is necessary for the data to be valid

The answer would be the last choice, "because this is necessary for the data to be valid."

Explanation:

This is because in an experiment, things must be controlled or monitored in most ways; otherwise, the result of the experiment will be different from what it was meant to be. An experiment should be as exact as possible. If this is not possible, results may be unreliable.

a community that experiences major changes undergoes progress

answer:

sequence 1- deletion

                  2- duplication

                  3- insertion

                  4- substitute

                  5- inversion