For preventing stds use a condom birth control or abstinence
C) all white blood cells because like aids hiv attacks the immune system slowly killing you until u have no immune system left
Breaking the body into systems is in most cases a lot easier for the students to understand instead of just doing it all at once
Answer:
Muscles move body parts by contracting and then relaxing. Muscles can pull bones, but they can't push them back to the original position. So they work in pairs of flexors and extensors. The flexor contracts to bend a limb at a joint.
Explanation:
Vaccinations were first used in the year 1796.
