for questions 7-9 imagine a segment in a plane use that information to help you answer the questions

how many midpoints does the segment have?
one
two
infinitely many
none

how many bisectors does the segment have?
one
two
infinitely many
none

how many lines in the plane are perpendicular bisectors of the segment?
one
two
infinitely many
none

every point on the perpendicular bisector of a segment is?
perpendicular to the endpoints
equidistant from the endpoints of that segment
parallel to the endpoints of that segment
a midpoint of the segment

at this point anything will do