Answer: Great things might be done, if men were wise.

Explanation: Exclamatory sentences are sentences that are used to convey emotion and they end with an exclamation mark. When it's changed to an assertive sentence, the statement is said in form of a declarative sentence that ends in a period. Here, the question exclaims that there are many things that can be done if men were wise. Any positive adjective like "great things", or "wonderful things" can be added here.