Which is more harmful primary or secondary pollutants

Primary pollutants and secondary pollutants can be more dangerous.

Explanation: The first are those that are emitted directly from a source, which can be natural (volcanic eruptions or fires, for example) or of anthropogenic origin (carbon monoxide from vehicles). Secondary pollutants, on the other hand, are not emitted directly.

secondary pollutants

Explanation:

Primary pollutants and secondary pollutants can be more dangerous. The first are those that are emitted directly from a source, which can be natural (volcanic eruptions or fires, for example) or of anthropogenic origin (carbon monoxide from vehicles). Secondary pollutants, on the other hand, are not emitted directly

b tumor cells have a cell wall instead of a membrane

explanation:

tumor cells different from normal cells because tumor cells have a cell wall instead of a membrane.