Vaccines contain a memory cells against the pathogen. b antibodies of the pathogen. c lymphokines. d t cells programmed to attack the pathogen. e antigens of the pathogen.

Adog begins walking at a speed of 6 kilometers per hour. after 1 hour, the dog is walking at a speed of 4 kilometers per hour. which is this an example of? a. positive acceleration b. negative acceleration c. speed