Which behavior can reduce one’s risk of acquiring a sexually transmitted infection (sti)?

dating older people
stopping casual contact with partners
having multiple sexual partners
communicating with sexual partner

How could you find out if that advice is based in scientific evidence?

Bloodborn pathogens are infectious microorganisms carried by what?

If a social worker goes around boasting to clients and co workers, it may make the listener feel inferior, judged, maybe insignificant how do you feel when someone is boastful and self absorbed when providing you a professional service? why?