Answer: peristalsis
Explanation:it's the contraction and relaxation of muscles as the bolus moves down the oesophagus
Organisms who happen to be best suited to an environment and reproduce most successfully will be consider successful in terms of natural selection.
Answer:
Option B
Explanation:
ODD means Oppositional Defiant Disorder while CD means Conduct disorder.
Without initial presence of defiant disorder symptoms, Oppositional defiant disorder are not precursor to the development of conduct disorder.
Oppositional Defiant Disorder and Conduct Disorder are much more predominant in boys than in girls.
According to reseaches carried out,to boys, Oppositional Defiant disorder is a precursor to conduct disorder.
It would be the respiratory system
B. Nitrogen oxygen, Oxygen, and argon
