Which of the following is a true statement?
mucus protects the stomach lining from digestive secretions.
protease breaks down lipids into fatty acids and glycerol.
lipase breaks down proteins in the small intestine.
pepsin is an antibacterial agent that kills some bacteria.

In an experiment examining the effects tai chi on arthritis pain, callahan (2010) selected a large sample of individuals with doctor-diagnosed arthritis. half of the participants immediately began a tai chi course and the other half (the control group) waited 8 weeks before beginning. at the end of 8 weeks, the individuals who had experienced tai chi had less arthritis pain that those who had not participated in the course.