Problem: House music:

The early 1990s additionally saw the rise in mainstream US popularity for house music. Pop recording artist Madonna's 1990 single "Vogue" became an international hit single and topped the US charts. The single is credited as helping to bring house music to the US mainstream.

What Madonna single is credited as helping bring US music to the mainstream?
---
A: unanswerable


Problem: Bern:

The etymology of the name Bern is uncertain. According to the local legend, based on folk etymology, Berchtold V, Duke of Zähringen, the founder of the city of Bern, vowed to name the city after the first animal he met on the hunt, and this turned out to be a bear. It has long been considered likely that the city was named after the Italian city of Verona, which at the time was known as Bern in Middle High German. As a result of the find of the Bern zinc tablet in the 1980s, it is now more common to assume that the city was named after a pre-existing toponym of Celtic origin, possibly *berna "cleft". The bear was the heraldic animal of the seal and coat of arms of Bern from at least the 1220s. The earliest reference to the keeping of live bears in the Bärengraben dates to the 1440s.

What is the earliest that they kept live bears in the Bärengraben?
---
A: 1440s.


Problem: Literature:

Maslow’s ‘‘Third Force Psychology Theory’’ even allows literary analysts to critically understand how characters reflect the culture and the history in which they are contextualized. It also allows analysts to understand the author’s intended message and to understand the author’s psychology. The theory suggests that human beings possess a nature within them that demonstrates their true “self” and it suggests that the fulfillment of this nature is the reason for living. It also suggests that neurological development hinders actualizing the nature because a person becomes estranged from his or her true self. Therefore, literary devices reflect a characters’s and an author’s natural self. In his ‘‘Third Force Psychology and the Study of Literature’’, Paris argues “D.H Lawrence’s “pristine unconscious” is a metaphor for the real self”. Thus Literature is a reputable tool that allows readers to develop and apply critical reasoning to the nature of emotions.

The theory states that at the center of humans beings is what?
---
A: a nature within them that demonstrates their true “self”


Problem: Slavs:

The word "Slavs" was used in the national anthem of the Slovak Republic (1939–1945), Yugoslavia (1943–1992) and the Federal Republic of Yugoslavia (1992–2003), later Serbia and Montenegro (2003–2006).

When was slavs used for the Yugoslavia and Montenegro anthem?
---
A:
unanswerable