In the human body the digestion of proteins takes place primarily in which two organs?
===
OPTIONS:
- Mouth and stomach
- Stomach and small intestine
- Liver and gall bladder
- Pancreas and large intestine

Stomach and small intestine

Earth rotates on its north-south axis. Which statement best describes one complete rotation?
===
OPTIONS:
- It takes six months and causes summer and winter seasons.
- It takes 24 hours and causes night and day.
- It takes 29 days, which represents one cycle of the Moon's phases.
- It takes 365 days, which represents one Earth year.

It takes 24 hours and causes night and day.

Which of the following is most responsible for the decay of dead organisms?
===
OPTIONS:
- water
- mammals
- microorganisms
- nitrogen
microorganisms