Input: Article: After returning to the United States, Kerry joined the Vietnam Veterans Against the War (VVAW). Then numbering about 20,000, VVAW was considered by some (including the administration of President Richard Nixon) to be an effective, if controversial, component of the antiwar movement. Kerry participated in the "Winter Soldier Investigation" conducted by VVAW of U.S. atrocities in Vietnam, and he appears in a film by that name that documents the investigation. According to Nixon Secretary of Defense Melvin Laird, "I didn't approve of what he did, but I understood the protesters quite well", and he declined two requests from the Navy to court martial Reserve Lieutenant Kerry over his antiwar activity.

Now answer this question: What VVAW investigation was Kerry involved in?

Output: the "Winter Soldier Investigation"

Input: Article: Improvisation once played an important role in classical music. A remnant of this improvisatory tradition in classical music can be heard in the cadenza, a passage found mostly in concertos and solo works, designed to allow skilled performers to exhibit their virtuoso skills on the instrument. Traditionally this was improvised by the performer; however, it is often written for (or occasionally by) the performer beforehand. Improvisation is also an important aspect in authentic performances of operas of Baroque era and of bel canto (especially operas of Vincenzo Bellini), and is best exemplified by the da capo aria, a form by which famous singers typically perform variations of the thematic matter of the aria in the recapitulation section ('B section' / the 'da capo' part). An example is Beverly Sills' complex, albeit pre-written, variation of Da tempeste il legno infranto from Händel's Giulio Cesare.

Now answer this question: What once played an important role in classical music?

Output: Improvisation

Input: Article: China, France, Russia, the United Kingdom and the United States are often referred to as great powers by academics due to "their political and economic dominance of the global arena". These five nations are the only states to have permanent seats with veto power on the UN Security Council. They are also the only recognized "Nuclear Weapons States" under the Nuclear Non-Proliferation Treaty, and maintain military expenditures which are among the largest in the world. However, there is no unanimous agreement among authorities as to the current status of these powers or what precisely defines a great power. For example, sources have at times referred to China, France, Russia and the United Kingdom as middle powers.

Now answer this question: What treaty addresses nuclear weapons?

Output:
Nuclear Non-Proliferation Treaty