Answer:
I'm pretty sure it is B, because of natural selection
C. Organ System
Like said in the definition above, an organ system is a group of organs working together to perform a specific function for the organism.
hope this helps !! have a great day :))
Answer:
Weakening of digestive smooth muscle with age can cause constipation.
Explanation:
Smooth muscles in the digestive system have the role to move food down the tract via radially symmetrical contractions (peristalsis). With age, the function of smooth muscles reduces, causing the food to move more slowly through the alimentary canal (digestive tract). As a consequence, water gets absorbed from food waste, which can cause constipation.
It would be probably be 1, as the recommended would be the average
D) It can only be used in areas with specific kinds of rivers.
