During the 1920's The United States went through a thriving economic period (until 1929) and this caused Americans to spend more money in leisure, including sports and different types of entertainment and activities.
Because of all these things, sports became a national pastime and people could follow different sports by:
- Attending games
- Following teams in the newspapers
- Reading about teams in magazine reports
- Listening to games on the radio
Several of these questions are opinion, so I can't really help with those, but I can answer the first one.
After World War I, the League of Nations was created to try to help keep the peace and solve problems between nations. The same went for the United Nations after World War II. There were also the treaties that ended the wars. (You'll have to decide whether or not these were actually successful.)
It’s D It created standardized rules regarding trade among
states.