When a warm air mass is caught between two cooler air masses, what is this type of front called? i've been stuck on this for a while lol

Ineed asap with this question as well organisms evolve, through the process of natural selection, in ways that enable them to live successfully in their environments. choose three biomes or aquatic ecosystems and describe how abiotic factors have influenced the organisms that live there

What are two ways in which waves erode the land?

What must be true for natural selection to heppen