A)amino acid is the correct answer
I'm pretty sure the answer is true. Hope this helps!
The effects of exercise on the circulatory system. This provides the muscles with the necessary oxygen and nutrients to provide the muscles with energy. During exercise strokevolume increases because: more blood is sent back to the heart due to the muscles squeezing blood in the veins. and I'll try to answer the other one just wait
Trace fossils represent things that were alive, it could be footprints, or bones.
I think this option fits best:
"<span>Evidence that animals were at some time in the area."</span>
