2. Muscles a. work in pairs.
b. move bones by relaxing.
c. get smaller when exercised.
d. All of the above

What is the difference in the phisical activity requirements for achieving healt benefits and performance?

The germs that cause infections are mainly spread in what three ways? a. immunization, mucous membranes, not washing hands b. germ-laden droplets, direct contact with body fluids, insects c. hand hygiene, sickness, immunization d. not enough sleep, low oral hygiene, germs

What is the difference between muscular strength and muscular endurance? a. strength refers to mobility of joints, while endurance refers to muscular force. b. strength refers to percentage of body fat, while endurance refers to sustaining activity over time. c. strength refers to muscular force, while endurance refers to sustaining activity over time. d. strength refers to the quality of physical performance, while endurance refers to mobility of joints.