Problem: By the 1990s Mexico City had become infamous as one of the world's most polluted cities; however the city has become a model for dramatically lowering pollution levels. By 2014 carbon monoxide pollution had dropped dramatically, while levels of sulfur dioxide and nitrogen dioxide were nearly three times lower than in 1992. The levels of signature pollutants in Mexico City are similar to those of Los Angeles.[citation needed] Despite the cleanup, the metropolitan area is still the most ozone-polluted part of the country, with ozone levels 2.5 times beyond WHO-defined safe limits.
When Mexico one of the worst cities in terms of pollution?
The answer is the following: 1990s

After the first two months of the conflict, South Korean forces were on the point of defeat, forced back to the Pusan Perimeter. In September 1950, an amphibious UN counter-offensive was launched at Inchon, and cut off many of the North Korean attackers. Those that escaped envelopment and capture were rapidly forced back north all the way to the border with China at the Yalu River, or into the mountainous interior. At this point, in October 1950, Chinese forces crossed the Yalu and entered the war. Chinese intervention triggered a retreat of UN forces which continued until mid-1951. After these dramatic reversals of fortune, which saw Seoul change hands four times, the last two years of conflict became a war of attrition, with the front line close to the 38th parallel. The war in the air, however, was never a stalemate. North Korea was subject to a massive bombing campaign. Jet fighters confronted each other in air-to-air combat for the first time in history, and Soviet pilots covertly flew in defense of their Communist allies.
In 1950, what country got involved in the war?
China

Input: Slavs
The word "Slavs" was used in the national anthem of the Slovak Republic (19391945), Yugoslavia (19431992) and the Federal Republic of Yugoslavia (19922003), later Serbia and Montenegro (20032006).

When was the word "Slavs" used in the national anthem of Serbia and Montenegro?
Output: 20032006

Input: Article: Raised in Chicago, West briefly attended art school before becoming known as a producer for Roc-A-Fella Records in the early 2000s, producing hit singles for artists such as Jay-Z and Alicia Keys. Intent on pursuing a solo career as a rapper, West released his debut album The College Dropout in 2004 to widespread commercial and critical success, and founded record label GOOD Music. He went on to explore a variety of different musical styles on subsequent albums that included the baroque-inflected Late Registration (2005), the arena-inspired Graduation (2007), and the starkly polarizing 808s & Heartbreak (2008). In 2010, he released his critically acclaimed fifth album, the maximalist My Beautiful Dark Twisted Fantasy, and the following year he collaborated with Jay-Z on the joint LP Watch the Throne (2011). West released his abrasive sixth album, Yeezus, to further critical praise in 2013. Following a series of recording delays and work on non-musical projects, West's seventh album, The Life of Pablo, was released in 2016.

Now answer this question: With which artists that Kanye formerly produced for did he go on to collaborate with?

Output: Jay-Z

Article: There has recently been an effort to reevaluate the influence of the Bible on Western constitutional law. In the Old Testament, there was some language in Deuteronomy imposing restrictions on the Jewish king, regarding such things as how many wives he could have, and how many horses he could own for his personal use. According to Professor Bernard M. Levinson, "This legislation was so utopian in its own time that it seems never to have been implemented...." The Deuteronomic social vision may have influenced opponents of the divine right of kings, including Bishop John Ponet in sixteenth-century England.

Question: What principle did the restrictions on the right of kings, as detailed in Deuteronomy, influence later opposition?
Ans: divine right of kings

Input: Pope John XXIII
The 50th anniversary of his death was celebrated on 3 June 2013 by Pope Francis, who visited his tomb and prayed there, then addressing the gathered crowd and spoke about the late pope. The people that gathered there at the tomb were from Bergamo, the province where the late pope came from. A month later, on 5 July 2013, Francis approved Pope John XXIII for canonization, along with Pope John Paul II without the traditional second miracle required. Instead, Francis based this decision on John XXIII's merits for the Second Vatican Council. On Sunday, 27 April 2014, John XXIII and Pope John Paul II were declared saints on Divine Mercy Sunday.

When was the 50th anniversary of his death?
Output:
3 June 2013