In this task, you are given a question and a context passage. You have to answer the question based on the given passage.
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Question: What vehicle could you have that you would need lower pressure boiler feed water?, Context: The Rankine cycle and most practical steam engines have a water pump to recycle or top up the boiler water, so that they may be run continuously. Utility and industrial boilers commonly use multi-stage centrifugal pumps; however, other types are used. Another means of supplying lower-pressure boiler feed water is an injector, which uses a steam jet usually supplied from the boiler. Injectors became popular in the 1850s but are no longer widely used, except in applications such as steam locomotives.

Answer: steam locomotives


Question: Which is larger, cliques or crowds?, Context: Adolescents tend to associate with "cliques" on a small scale and "crowds" on a larger scale. During early adolescence, adolescents often associate in cliques, exclusive, single-sex groups of peers with whom they are particularly close. Despite the common notion that cliques are an inherently negative influence, they may help adolescents become socially acclimated and form a stronger sense of identity. Within a clique of highly athletic male-peers, for example, the clique may create a stronger sense of fidelity and competition. Cliques also have become somewhat a "collective parent," i.e. telling the adolescents what to do and not to do. Towards late adolescence, cliques often merge into mixed-sex groups as teenagers begin romantically engaging with one another. These small friend groups then break down further as socialization becomes more couple-oriented. On a larger scale, adolescents often associate with crowds, groups of individuals who share a common interest or activity. Often, crowd identities may be the basis for stereotyping young people, such as jocks or nerds. In large, multi-ethnic high schools, there are often ethnically-determined crowds. While crowds are very influential during early and middle adolescence, they lose salience during high school as students identify more individually.

Answer: crowds


Question: Hayek learned psychology and?, Context: In The Sensory Order: An Inquiry into the Foundations of Theoretical Psychology (1952), Hayek independently developed a "Hebbian learning" model of learning and memory – an idea which he first conceived in 1920, prior to his study of economics. Hayek's expansion of the "Hebbian synapse" construction into a global brain theory has received continued attention in neuroscience, cognitive science, computer science, behavioural science, and evolutionary psychology, by scientists such as Gerald Edelman, and Joaquin Fuster.

Answer:
economics