Answer:
Amphibians
Explanation:
They had just shown up during the Carboniferous period and were still living in the water.
The removal of the producers would cause the collapse of the entire food web. Primary consumers or herbivores, which feed on producers directly, would die off.
There are three stages in the life cycle of a spider : - the first is embryonic stage, then the larval stage and finally nympho- imginal stage.
The purpose of an indicator is to test how acidic or basic something is.