Problem: Extract the answer to the question from the following context. Question: What was Heiji Rebellion preceded by? Context: A struggle for succession in the mid-twelfth century gave the Fujiwara an opportunity to regain their former power. Fujiwara no Yorinaga sided with the retired emperor in a violent battle in 1156 against the heir apparent, who was supported by the Taira and Minamoto (Hōgen Rebellion). In the end, the Fujiwara were destroyed, the old system of government supplanted, and the insei system left powerless as bushi took control of court affairs, marking a turning point in Japanese history. In 1159, the Taira and Minamoto clashed (Heiji Rebellion), and a twenty-year period of Taira ascendancy began.

A: Hōgen Rebellion


Problem: Extract the answer to the question from the following context. Question: What comes first, antibodies or antigens? Context: The humoral (antibody) response is defined as the interaction between antibodies and antigens. Antibodies are specific proteins released from a certain class of immune cells known as B lymphocytes, while antigens are defined as anything that elicits the generation of antibodies ("anti"body "gen"erators). Immunology rests on an understanding of the properties of these two biological entities and the cellular response to both.

A: antigens


Problem: Extract the answer to the question from the following context. Question: Which is not a person: Spencer, European, or Hobbes? Context: Matthew Arnold contrasted "culture" with anarchy; other Europeans, following philosophers Thomas Hobbes and Jean-Jacques Rousseau, contrasted "culture" with "the state of nature". According to Hobbes and Rousseau, the Native Americans who were being conquered by Europeans from the 16th centuries on were living in a state of nature; this opposition was expressed through the contrast between "civilized" and "uncivilized." According to this way of thinking, one could classify some countries and nations as more civilized than others and some people as more cultured than others. This contrast led to Herbert Spencer's theory of Social Darwinism and Lewis Henry Morgan's theory of cultural evolution. Just as some critics have argued that the distinction between high and low cultures is really an expression of the conflict between European elites and non-elites, some critics have argued that the distinction between civilized and uncivilized people is really an expression of the conflict between European colonial powers and their colonial subjects.

A: European


Problem: Extract the answer to the question from the following context. Question: Why does it seem odd that the ships are retiring? Context: The Royal Navy is constructing two new larger STOVL aircraft carriers, the Queen Elizabeth class, to replace the three now retired Invincible-class carriers. The ships are HMS Queen Elizabeth and HMS Prince of Wales. They will be able to operate up to 40 aircraft on peace time operations with a tailored group of up to 50, and will have a displacement of 70,600 tonnes. HMS Queen Elizabeth is projected to commission in 2017 followed by Prince of Wales in about 2020. The ships are due to become operational starting in 2020. Their primary aircraft complement will be made up of F-35B Lightning IIs, and their ship's company will number around 680 with the total complement rising to about 1600 when the air group is embarked. The two ships will be the largest warships ever built for the Royal Navy.

A:
Invincible