Every human body hasn't uncountable number of this basic unit of a muscle known as what ?

Andrew loves to go camping and hiking in the fall. about two weeks after his last camping trip, he noticed an expanding red, target shaped, rash on his arm. to avoid this illness, andrew should have select one: a. boiled his water before drinking. b. avoided contact with ticks. c. avoided contact with fleas found on mice. d. camped only in the spring.