5. What are vertebrae?
A. small bones making up the backbone or spine
B. bones that the spinal cord runs through
C. bones that have joints allowing the spine to bend D. all of the above

What is the difference between an igneous, sedimentary and metamorphic rock

Is there any species that went extinct in recent years due to natural causes (not caused by human interaction). if so, what caused it?

Which description shows competition in an environment? an organism that feeds on some food an organism that finds a place to sleep three organisms of the same species living in an area three organisms battling over limited resources