Answer:
White blood cells are an important part of the immune system. HIV infects and destroys certain white blood cells called CD4+ cells. If too many CD4+ cells are destroyed, the body can no longer defend itself against infection. The last stage of HIV infection is AIDS (acquired immunodeficiency syndrome).
Explanation:
Answer:
true
Explanation:
you break the food down with your mouth to start digestion
Blood turns red when we start bleeding because the chemical composition of our blood changes when it reaches the air. This is known as oxidation, and no, it is probably not okay if your blood doesn't turn red once it reaches the outside of your body.
False it is false since pollution isn't only in the city
