Why should we practice the local methods of separation?

To obtain a desired component from the mixture

Explanation:

It is also important to be able to separate mixtures to be able to better understand how each component contributes to the properties, chemical and physical, of the resulting mixture.

a. a primary source combines several different accounts of an event. b. a primary source generally benefits from having been written after an event.

explanation:

a:

by the combination of an unlimited number of elements