Problem: Renewable energy commercialization:

Tax shifting has been widely discussed and endorsed by economists. It involves lowering income taxes while raising levies on environmentally destructive activities, in order to create a more responsive market. For example, a tax on coal that included the increased health care costs associated with breathing polluted air, the costs of acid rain damage, and the costs of climate disruption would encourage investment in renewable technologies. Several Western European countries are already shifting taxes in a process known there as environmental tax reform.

Several Western European companies are shifting taxes in a process known as what?
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A: environmental tax reform

Problem: Washington University in St. Louis:

The school has many nationally and internationally acclaimed scholars in social security, health care, health disparities, communication, social and health policy, and individual and family development. Many of the faculty have training in both social work and public health. The school's current dean is Edward F. Lawlor. In addition to affiliation with the university-wide Institute of Public Health, Brown houses 12 research centers. The Brown School Library collects materials on many topics, with specific emphasis on: children, youth, and families; gerontology; health; mental health; social and economic development; family therapy; and management. The library maintains subscriptions to over 450 academic journals.

How many academic journal subscriptions does the Brown School Library have for family therapy?
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A: unanswerable

Problem: Wood:

A knot is a particular type of imperfection in a piece of wood; it will affect the technical properties of the wood, usually reducing the local strength and increasing the tendency for splitting along the wood grain, but may be exploited for visual effect. In a longitudinally sawn plank, a knot will appear as a roughly circular "solid" (usually darker) piece of wood around which the grain of the rest of the wood "flows" (parts and rejoins). Within a knot, the direction of the wood (grain direction) is up to 90 degrees different from the grain direction of the regular wood.

Are knots usually lighter or darker than the surrounding wood?
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A: darker

Problem: Geological history of Earth:

The Earth of the early Archean (4,000 to 2,500 million years ago) may have had a different tectonic style. During this time, the Earth's crust cooled enough that rocks and continental plates began to form. Some scientists think because the Earth was hotter, that plate tectonic activity was more vigorous than it is today, resulting in a much greater rate of recycling of crustal material. This may have prevented cratonisation and continent formation until the mantle cooled and convection slowed down. Others argue that the subcontinental lithospheric mantle is too buoyant to subduct and that the lack of Archean rocks is a function of erosion and subsequent tectonic events.

During what period did the earths crust cooling allow the creation of plates?
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A:
Archean