I'm gonna say Chemical makeup and how they can be used.
Answer:
Explanation:
Check the dna of space rocks
The answer to the question ; Land ____ is a hazard in which an area of land sinks down due to removal of underground material is letter B. The Subsidence. So we should read it as, The land subsidence is a hazard in which area of land sinks down due to removal of underground material. B, Subsidence.
I think it’s c bc it say one way to make the earths coal supply last longer and you can build and use solar power plants