Statements: (a) All dogs are rats. (b) All rats are crows. (c) All crows are parrots. Conclusions: (I) All dogs are parrots. (II) Some parrots are dogs. (III) Some crows are dogs. (IV) All rats are dogs.

All the three Premises are Universal Affirmative (A-type).
All dogs are rats. ↔ All rats are crows.
A + A ⇒ A-type of Conclusion "All dogs are crows."
Conclusion III is converse of it.
All rats are crows. ↔ All crows are parrots.
A + A ⇒ A-type of Conclusion "All rats are parrots."
All dogs are crows. ↔ All crows are parrots.
A + A ⇒ A-type of Conclusion "All dogs are parrots."
This is Conclusion I.
Conclusion II is converse of it.