Problem: Brass, which is an alloy of copper and zinc, has been used since at least the 10th century BC in Judea and by the 7th century BC in Ancient Greece. Zinc metal was not produced on a large scale until the 12th century in India and was unknown to Europe until the end of the 16th century. The mines of Rajasthan have given definite evidence of zinc production going back to the 6th century BC. To date, the oldest evidence of pure zinc comes from Zawar, in Rajasthan, as early as the 9th century AD when a distillation process was employed to make pure zinc. Alchemists burned zinc in air to form what they called "philosopher's wool" or "white snow".
What early process was used to make zinc?
The answer is the following: distillation process

Problem: The investigation of the transmitted signals started immediately after the launch of Compass -M1 on 14 April 2007. Soon after in June 2007, engineers at CNES reported the spectrum and structure of the signals. A month later, researchers from Stanford University reported the complete decoding of the "I" signals components. The knowledge of the codes allowed a group of engineers at Septentrio to build the COMPASS receiver and report tracking and multipath characteristics of the "I" signals on E2 and E5B.
Who reported the complete decoding of the "I" signals components?
The answer is the following: researchers from Stanford University

Problem: Slack (2003) compares three groups that conducted biological research at Yale during overlapping periods between 1910 and 1970. Yale proved important as a site for this research. The leaders of these groups were Ross Granville Harrison, Grace E. Pickford, and G. Evelyn Hutchinson, and their members included both graduate students and more experienced scientists. All produced innovative research, including the opening of new subfields in embryology, endocrinology, and ecology, respectively, over a long period of time. Harrison's group is shown to have been a classic research school; Pickford's and Hutchinson's were not. Pickford's group was successful in spite of her lack of departmental or institutional position or power. Hutchinson and his graduate and postgraduate students were extremely productive, but in diverse areas of ecology rather than one focused area of research or the use of one set of research tools. Hutchinson's example shows that new models for research groups are needed, especially for those that include extensive field research.
What information did Hutchinson's model provide?
The answer is the following: new models for research groups are needed

Problem: The economy is a mixture of village agriculture and handicrafts, an industrial sector based largely on petroleum, support services, and a government characterized by budget problems and overstaffing. Petroleum extraction has supplanted forestry as the mainstay of the economy. In 2008, oil sector accounted for 65% of the GDP, 85% of government revenue, and 92% of exports. The country also has large untapped mineral wealth.
What percentage of the Congo's gross domestic product did petroleum account for in 2008?
The answer is the following:
65%