Problem: High-definition television:

The term high definition once described a series of television systems originating from August 1936; however, these systems were only high definition when compared to earlier systems that were based on mechanical systems with as few as 30 lines of resolution. The ongoing competition between companies and nations to create true "HDTV" spanned the entire 20th century, as each new system became more HD than the last.In the beginning of the 21st century, this race has continued with 4k, 5k and current 8K systems.

During which entire century were companies and nations trying to achieve true SDTV?
---
A: unanswerable

Problem: Modern history:

In Latin America in the 1970s, leftists acquired a significant political influence which prompted the right-wing, ecclesiastical authorities and a large portion of the individual country's upper class to support coup d'etats to avoid what they perceived as a communist threat. This was further fueled by Cuban and United States intervention which led to a political polarization. Most South American countries were in some periods ruled by military dictatorships that were supported by the United States of America. In the 1970s, the regimes of the Southern Cone collaborated in Operation Condor killing many leftist dissidents, including some urban guerrillas. However, by the early 1990s all countries had restored their democracies.

Where did the United States support dictatorships in the 1970"s?
---
A: South American countries

Problem: Annelid:

As in arthropods, each muscle fiber (cell) is controlled by more than one neuron, and the speed and power of the fiber's contractions depends on the combined effects of all its neurons. Vertebrates have a different system, in which one neuron controls a group of muscle fibers. Most annelids' longitudinal nerve trunks include giant axons (the output signal lines of nerve cells). Their large diameter decreases their resistance, which allows them to transmit signals exceptionally fast. This enables these worms to withdraw rapidly from danger by shortening their bodies. Experiments have shown that cutting the giant axons prevents this escape response but does not affect normal movement.

What worms are very slow to retreat from danger?
---
A: unanswerable

Problem: Beyonce:

Her fourth studio album 4 was released on June 28, 2011 in the US. 4 sold 310,000 copies in its first week and debuted atop the Billboard 200 chart, giving Beyonce her fourth consecutive number-one album in the US. The album was preceded by two of its singles "Run the World (Girls)" and "Best Thing I Never Had", which both attained moderate success. The fourth single "Love on Top" was a commercial success in the US. 4 also produced four other singles; "Party", "Countdown", "I Care" and "End of Time". "Eat, Play, Love", a cover story written by Beyonce for Essence that detailed her 2010 career break, won her a writing award from the New York Association of Black Journalists. In late 2011, she took the stage at New York's Roseland Ballroom for four nights of special performances: the 4 Intimate Nights with Beyonce concerts saw the performance of her 4 album to a standing room only.

How many copies did the album sell in its first week?
---
A:
310,000 copies