How do the muscles in the human body with movement? a. muscles contract and thus pull on bones to cause movement. b. they bend the bones. c. the bones are contracted by the muscles. d. they push the bones apart using ligaments.

Dr. arenas is a scientist who has been trying to determine if increasing pressure will increase the sound that occurs when two chemicals explode. it measures the volume of the sound that occurs at the minimum pressure at which the explosion will occur. it then increases the pressure and measures the volume of the explosions that occur. what kind of investigation is the scientist conducting?