How are c3, c4, and cam alike? A: they all measure color/color intensity
B: They are all ways to change sunlight to chemical energy
C: They are all ways to decompose dead organic matter
D: They are all formulae for plant cell wall materials ​

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.