Question

When can a source be both primary and secondary​

Answer 1

Primary and secondary categories are often not fixed and depend on the study or research you are undertaking. For example, newspaper editorial/opinion pieces can be both primary and secondary. If exploring how an event affected people at a certain time, this type of source would be considered a primary source

Answer 2

Answer:

☞A primary pollutant is one that is emitted directly from a source. Secondary pollutants are formed when primary pollutants interact with each other in the atmosphere.