Explain how you and a friend could be exposed to the same microbes and only one of you becomes sick.

One is probably because your friend has a stronger immune system than you and is able t fight the bacteria infection. The other is probably that your friend is also infected but does not show any symptoms of the infection, in what is referred to as latent infection. The bacteria enters a lysogenic cycle in your friend’s body rather than the more virulent lytic cycle (that happens to you).