If the infection has not been cured before you have oral sex, then yes you can get the std that she used to have.
Depends. if its a virus, then they will never go away. but if the STD is a bacteria, then you have to go on antibiotics.
Go to the doctor.
They are both technically right, but the majority of people would say 'an' STD. When talking about something that begins with a vowel-sounding letter, we tend to use 'an' - it just sounds better to...
HIV and HBV are connected to needle use. Neither of these viral infections are curable.