By the unequal heating of earths surface
I think I’ll go with C. long dry cold winters
Answer:Tissue
Explanation:Heart muscle cells beat in unison to push blood in timing with the rhythm of the heart, at the direction of nearby nerve cells. These muscle cells could best be called. Tissue. As cell division proceeds, the cells increase in number, but also become specialized in structure and function.
any sort of ancient fossil would be my quess. also i am on achallenge to see how many friends i can get on brainly so pls friend me