試題詳解

25. Which one of the following statements is NOT true regarding the respiration system?
(A) In fish gills, more than 80% of the O2 dissolved in the water is removed as water passes over the respiratory surface.
(B) Respiratory surfaces are always thin and moist.
(C) Fish gills use a countercurrent exchange system to increase blood flow.
(D) In human lungs, cilia and mucus line the epithelium of the air ducts and move particles up to the pharynx.