22. Describe the four main characteristics of an ani- mal's respiratory surface.

23. Trace the pathway of air through the human res-
piratory system, from the nostrils to the lungs. At
what point within the lungs do the oxygen mol-
ecules really enter the body?

d bonding propertys

explanation:

carbon can form so many different compounds not just with oxygen

bradykinin is a physiologically and pharmacologically active peptide of the kinin group of proteins, consisting of nine amino acids.

flooding wildfire landslides climate change the factors listed have an immediate effect on the animal populations found in any habitat. the four factors would lead to a death. b emigration. eliminate c immigration. d mutations.