---- discovery of insulin, it was not possible to treat diabetes.

---- discovery of insulin, it was not possible to treat diabetes. Correct Answer Prior to the

Prior (পূর্বে, আগে) এরপর preposition বসে, অর্থাৎ prior to something. একমাত্র option (গ) তে prior এরপর to আছে। তাই correct answer (গ)।

Related Questions

_______ discovery of insulin, it was not possible _______ treat diabetes.
___discovery of insulin , it was not possible to treat diabetes