Ineed with these question can u pl.

19. The human respiratory system is a series of organs responsible for taking in oxygen and expelling carbon dioxide.

20. nose, mouth, pharynx, larynx, trachea, bronchi, and lungs

21. Can't answer

22.Digestion is the breakdown of food into small molecules, which are then absorbed into the body.

23. mouth, esophagus, stomach, small intestine, large intestine

24. Don't Know

.) the observation by semmelweis that more mothers died of childbed fever when their doctors also worked in the morgue

d₁ = displacement of tern from arctic to antarctic = 11000 miles

d₂ = displacement of tern from antarctic to arctic =   - 11000 miles

d = total displacement for the journey

total displacement for the journey is given as

d = d₁ + d₂

d = 11000 + (-11000)

d = 0 miles

t₁ = time of travel from arctic to antarctic = 3 months = 3 x 30 days = 90 days

t₂ = time of travel from antarctic to arctic = 3 months = 3 x 30 days = 90 days

t = total time of travel

total time of travel is given as

t = t₁ + t₂

t = 90 + 90

t = 180 days

average velocity is given as

average velocity = total displacement/ total time

v = d/t

v = 0/180

v = 0 miles/day