The sonata form.
In particular, the sonata form typically was the structure of the first movement of classical symphonies. Sonata form follows this pattern:
Exposition: Two musical themes are set forth or "exposed" to the listeners. (Thus the label "exposition.") The first theme is usually strong, the second quieter, more gentle.
Development: Then the two themes are explored or "developed" in various ways and played off of one another.
Recapitulation: Finally, the themes are restated in the order in which they were introduced in the exposition section and reaffirmed as the musical themes of the movement.
The primary aims of the League of Nations: Maintain the peace process and prevent future wars.
Details:
An organization such as the League of Nations was the signature idea of US President Woodrow Wilson. He had laid out 14 Points for establishing and maintaining world peace following the Great War (World War I). Point #14 was the establishment of an international peacekeeping association. The Treaty of Versailles adopted that idea, and the League of Nations was established in 1920. [Notably, the United States never joined the League, because the US Senate did not ratify the Treaty of Versailles.]
The League of Nations had set out clear goals for what it intended to do. The main aims of the League were disarmament across nations, preventing war through collective security of the international community, settling disputes between countries through negotiation, and improving welfare of people around the globe. But it proved unable to meet those goals. The United Nations, formed after World War II, has similar goals, and has been more effective in its efforts -- though there are still plenty of people who criticize the UN's effectiveness.
The Fugitive Slave Acts required for the capture and return of runaway slaves within the territory of the United States, the escaped slaves were to be returned to their owners and often had harsh punishments.
The answer is the 1st one.
It was a period of rapid economic and social transformation.
(the time social, artistic, and culture dynamism began to prosper.)
