Here are all of the blanks filled in:
1. (Statement) AC is the perpendicular bisector of BD.
3. (Statement) BC is congruent to DC. (Reason) Definition of Congruence.
4. (Reason) Definition of a perpendicular bisector.
5. (Reason) Right Angles are Congruent.
6. (Statement) AC is congruent to AC.
7. (Statement) Triangle ABC is congruent to Triangle ADC. (Reason) SAS Congruence Theorem
Hope this helps!