What do all cells need in order to function

Astructural difference between the trachea and esophagus that prevents the trachea from collapsing is the presence of: a) smooth muscle b) skeletal muscle c) respiratory cilia d) rings of cartilage

Whic component of physical fitness is skill related?

Although animals share many common characteristics, there is also a great amount of diversity found in animals. which animals are ectothermic, obtain dissolved oxygen in water through gills, have scales, have fins, and live in water?