I only have enough time for 1-4 sorry :(.
1) line AB and line CD
2) line AC and line CD
3) No, because they intersect; parallel lines do not intersect.
4) No. There is not enough information to prove this because it is not marked as a 90 degree angle (perpendicular lines form 90 degree angles)
I think these are right but please correct me if I am wrong! :)
