Answer:
true they do I yes they do
Answer: it's part of the immune system that focuses on specific foreign particles. Rather than generically attack any antigens, T cells circulate until they encounter their specific antigen. As such, T cells play a critical part in immunity to foreign substances !
Explanation:
I think D, not sure though!
Answer:
Fluorine has an electronegativity of 4, which is the highest an element has. Makes it a pretty dangerous substance to work with
