The body's defense and surveillance network of cells and chemicals that fight off bacteria and viruses is called the:

Which of the following statements is true?

a. Neither nicotine nor caffeine is dangerous. b. Nicotine is far more dangerous than caffeine. c. Caffeine is far more dangerous than nicotine. d. Both caffeine and nicotine are equally dangerous.

Len is constantly anxious. To relieve his anxiety, he counts silently to himself. He may count

his breaths per minute, or he may just count the seconds as they tick by. Just the act of counting seems to relieve his anxiety. Len's counting behaviors represent a(n) ______. a. delusion c. obsession b. compulsion d. abreaction