Logic Questions

Can any please help me solve my logic proofs! My final is comming up and I need help solving problems of my study guide! I am posting the ones I am most confused about if anyone can help with any of them I would greatly appreciate it!
1. C: D
P1: A ∨ B
P2: C ⊃ A
P3: (B • ~C) ⊃ (D • ~C)
P4: ~A
_____________________________________________________
2. C: A ⊃ E
P1: A ⊃ (B • C)
P2: (B ∨ D) ⊃ E
_____________________________________________________
3. C: ~B
P1: C ≡ D
P2: B ⊃ (D • E)
P3: ~C ∨ ~D

Please Please Please Help!!