Here is a question about this article: Greenhouses convert solar light to heat, enabling year-round production and the growth (in enclosed environments) of specialty crops and other plants not naturally suited to the local climate. Primitive greenhouses were first used during Roman times to produce cucumbers year-round for the Roman emperor Tiberius. The first modern greenhouses were built in Europe in the 16th century to keep exotic plants brought back from explorations abroad. Greenhouses remain an important part of horticulture today, and plastic transparent materials have also been used to similar effect in polytunnels and row covers.
What is the answer to this question: What was one of the first uses of a greenhouse?
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So... produce cucumbers year-round for the Roman emperor Tiberius


Here is a question about this article: Society throughout Europe was disturbed by the dislocations caused by the Black Death. Lands that had been marginally productive were abandoned, as the survivors were able to acquire more fertile areas. Although serfdom declined in Western Europe it became more common in Eastern Europe, as landlords imposed it on those of their tenants who had previously been free. Most peasants in Western Europe managed to change the work they had previously owed to their landlords into cash rents. The percentage of serfs amongst the peasantry declined from a high of 90 to closer to 50 per cent by the end of the period. Landlords also became more conscious of common interests with other landholders, and they joined together to extort privileges from their governments. Partly at the urging of landlords, governments attempted to legislate a return to the economic conditions that existed before the Black Death. Non-clergy became increasingly literate, and urban populations began to imitate the nobility's interest in chivalry.
What is the answer to this question: By the end of this period, about what percentage of Western Europeans were serfs?
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So... 50


Here is a question about this article: The discipline of ecology typically traces its origin to the synthesis of Darwinian evolution and Humboldtian biogeography, in the late 19th and early 20th centuries. Equally important in the rise of ecology, however, were microbiology and soil science—particularly the cycle of life concept, prominent in the work Louis Pasteur and Ferdinand Cohn. The word ecology was coined by Ernst Haeckel, whose particularly holistic view of nature in general (and Darwin's theory in particular) was important in the spread of ecological thinking. In the 1930s, Arthur Tansley and others began developing the field of ecosystem ecology, which combined experimental soil science with physiological concepts of energy and the techniques of field biology. The history of ecology in the 20th century is closely tied to that of environmentalism; the Gaia hypothesis, first formulated in the 1960s, and spreading in the 1970s, and more recently the scientific-religious movement of Deep Ecology have brought the two closer together.
What is the answer to this question: The discipline of ecology is a combination of what two subjects?
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So...
Darwinian evolution and Humboldtian biogeography