I've been stuck on this for about 30 minutes and I'm just getting even more confused with it. I think I know the answer but it keep saying I correct.

Which statement about the immune system is false? a. lymphocytes reduce inflammation, b. b cells remember specific pathogens. c. most white blood cells kill bacteria d. white blood cells are made in lymph nodes.

What is the difference between the conducting zone and the respiratory zone of the respiratory system? the conducting zone is a series of cavities and tubes that move air to the respiratory zone where gases exchange with the bloodstream. the conducting zone exchanges gases between the lungs and the alveoli and the respiratory zone is a series of cavities and tubes that move air to the conducting zone. the conducting zone moves oxygen into the cells and the respiratory zone takes carbon dioxide away from the cells. the conducting zone moves oxygen into the bloodstream and the respiratory zone takes carbon dioxide away from the bloodstream.

Which of the following can be reduced by the use of renewable energy sources? a. social costs b. economic costs c. environmental costs d. all of the above select the best answer from the choices provided a b c d