Gamma rays have wavelengths of in the range of meters.
a 10-20
b 1012
C 10-4
d 10-12

The distribution of related animals and plants across the world

Guard cells control which event? the growth of plants capture of solar energy gas exchange in leaves water absorption in roots

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.