What was the significance of collisions of dust, rock, and ice during earth’s formation?
a. to modify the density of materials present on earth
b. to facilitate heat absorption from the surrounding space
c. to blow away a strong burst of particles from the first atmosphere
d. to harden materials to form different parts of earth’s layers

Agene in a type of bacteria when the ses bacteria reproduce asexually this mutation can only be inherited by

The transport tubes for food coming down the plants are called?

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.