i need help to answer these Q

1-List 2 mechanisms for generating immunoglobulin diversity

2-Give an advantage and a disadvantage of N-region nucleotide additions.

3-What are advantages and disadvantages of not getting the flu vaccine

4-What are advantages and disadvantages of not getting the flu vaccine

5-What advantage could there be in having an immune system that generates billions of lymphocytes that do not recognize any known infectious agent?