Your answer is B.
It's called an occluded front where the cold air meets the warm air underneath it. Hot air rises over cold air. :) Hope this helps you.
~Hello there!
Your question: What substance is considered a building block for all living things?
Your answer: Carbon is the substance that is considered s building block for all living things.
Any questions ^?
Happy Studying!
It is soil after wind for example wind storm causes to soil erosion
