Answer:
immune system
Explanation:
The adaptive immune system reacts specifically to pathogens (germs). It is able to recognize attacking pathogens and fights against certain antigens or foreign substances. The next time a known antigen is encountered, the adaptive immune system can respond faster.
The heads are expected 5 times and the tails 5 times, it is a 50/50 chance for both.
Look on google for a venn diagram of the 2 things you are comparing and then use those answers