Why can two igneous rocks have the same materials but different names?

7th grade question (easy) look at the diagram of the food web. the arrows mean eaten by. what would happen if the number of snakes went down? answer choices are in the image.

The eruption of a nearby volcano causes a prairie ecosystem to receive a lot less sunlight.which of these is the most likely effect on the ecosystem? a-an increase in biodiversity. b-an increase in immigration to the area. c-a decrease in available water. d-a decrease in plant growth.

What are two ways that harvesting algae from the ocean may benefit human society? how might the harvest of algae negatively impact the ocean communities where that algae grows? how could this be prevented?