A

al s3x the riskiest s3xual activity for HIV transmission. (Haha sorry for the pi and 3s it won't let me submit some of those words)
The human heart has only 4 chambers. Left and right atria and left and right ventricles.
Answer:
True; all cells in a mature embryo can develop into muscle.
Explanation:
Aerobic respiration is producing of cellular energy involving oxygen.
Anaerobic respiration is respiration using electrons through molecular oxygen.
I don't think so, because for every action there is an equal and opposite reaction.
Hope this helps! :)