Problem: In 1937, the Empire of Japan started a full-scale invasion of China after invading Manchuria in 1931, beginning the Second Sino-Japanese War (often considered a theatre of World War II). Their troops occupied Nanjing in December and carried out the systematic and brutal Nanking Massacre (the "Rape of Nanking"). Even children, the elderly, and nuns are reported to have suffered at the hands of the Imperial Japanese Army. The total death toll, including estimates made by the International Military Tribunal for the Far East and the Nanjing War Crimes Tribunal, was between 300,000 and 350,000. The city itself was also severely damaged during the massacre. The Nanjing Massacre Memorial Hall was built in 1985 to commemorate this event.
When did Japan invade all of China?
The answer is the following: 1937

Problem: Bilateral treaties are concluded between two states or entities. It is possible, however, for a bilateral treaty to have more than two parties; consider for instance the bilateral treaties between Switzerland and the European Union (EU) following the Swiss rejection of the European Economic Area agreement. Each of these treaties has seventeen parties. These however are still bilateral, not multilateral, treaties. The parties are divided into two groups, the Swiss ("on the one part") and the EU and its member states ("on the other part"). The treaty establishes rights and obligations between the Swiss and the EU and the member states severally—it does not establish any rights and obligations amongst the EU and its member states.[citation needed]
Is it possible for a bilateral treaty to have more than two parties?
The answer is the following: It is possible

Problem: There are 20 clubs in the Premier League. During the course of a season (from August to May) each club plays the others twice (a double round-robin system), once at their home stadium and once at that of their opponents, for a total of 38 games. Teams receive three points for a win and one point for a draw. No points are awarded for a loss. Teams are ranked by total points, then goal difference, and then goals scored. If still equal, teams are deemed to occupy the same position. If there is a tie for the championship, for relegation, or for qualification to other competitions, a play-off match at a neutral venue decides rank. The three lowest placed teams are relegated into the Football League Championship, and the top two teams from the Championship, together with the winner of play-offs involving the third to sixth placed Championship clubs, are promoted in their place.
How many total games does each club in the Premier League play per season?
The answer is the following: 38

Problem: The signatures of the parties' representatives follow at the very end. When the text of a treaty is later reprinted, such as in a collection of treaties currently in effect, an editor will often append the dates on which the respective parties ratified the treaty and on which it came into effect for each party.
Each party must have done what in order for the treaty to come into effect?
The answer is the following:
ratified the treaty