Answer:
option d is correct. the existence of land bridges between continents.
Explanation:
landland bridge theory which was used to explain why species would end up continents over, such as mammoth travelling to North America, thisthis theory was based on the idea that water eventually Rose to cover these bridges rather than the at having individual plates that moved away from each other.
every cell has work to do but different cells may have different jobs in multicellular organisms, cell with the same type of job often work together. These group of specialized cell from tissue in turn, tissue often group together to form larger units called organs the heart is an organ; so is the stomach.
Answer:
D. Oral cavity to the trachea to the larynx to the right and left main bronchi.
Explanation:
