A study of 100 injection drug users who tested negative for HIV infection at enrollment had their HIV status retested at 3-month intervals over a 2-year follow-up period. All of the injection drug users were followed for the entire 2-year period. None died and none were lost to follow-up. Required:
What frequency measures of HIV infection can be calculated at the end of the study?

Frankie is having difficulty developing a friendship with histeammate curtis. whenever frankie invites curtis to hangout with him at the park, curtis always says that he's busy.what is most likely preventing a healthy relationship fromforming? a)the boys are not being generous with their time andeffort.b)the boys are not communicating.c)both boys are too busy.d)the boys are on different teams.