Problem: Wood:

The structure of hardwoods is more complex. The water conducting capability is mostly taken care of by vessels: in some cases (oak, chestnut, ash) these are quite large and distinct, in others (buckeye, poplar, willow) too small to be seen without a hand lens. In discussing such woods it is customary to divide them into two large classes, ring-porous and diffuse-porous.

Besides ring-porous, what's the other class hardwoods are often divided into?
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A: diffuse-porous

Problem: Comcast:

Comcast has also earned a reputation for being anti-union. According to one of the company's training manuals, "Comcast does not feel union representation is in the best interest of its employees, customers, or shareholders". A dispute in 2004 with CWA, a labor union that represented many employees at Comcast's offices in Beaverton, Oregon, led to allegations of management intimidating workers, requiring them to attend anti-union meetings and unwarranted disciplinary action for union members. In 2011, Comcast received criticism from Writers Guild of America for its policies in regards to unions.

What does the initialism CWA stand for?
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A: unanswerable

Problem: Lancashire:

The county was established in 1182, later than many other counties. During Roman times the area was part of the Brigantes tribal area in the military zone of Roman Britain. The towns of Manchester, Lancaster, Ribchester, Burrow, Elslack and Castleshaw grew around Roman forts. In the centuries after the Roman withdrawal in 410AD the northern parts of the county probably formed part of the Brythonic kingdom of Rheged, a successor entity to the Brigantes tribe. During the mid-8th century, the area was incorporated into the Anglo-Saxon Kingdom of Northumbria, which became a part of England in the 10th century.

When was Lancashire established?
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A: 1182

Problem: Solar energy:

In the last two decades, photovoltaics (PV), also known as solar PV, has evolved from a pure niche market of small scale applications towards becoming a mainstream electricity source. A solar cell is a device that converts light directly into electricity using the photoelectric effect. The first solar cell was constructed by Charles Fritts in the 1880s. In 1931 a German engineer, Dr Bruno Lange, developed a photo cell using silver selenide in place of copper oxide. Although the prototype selenium cells converted less than 1% of incident light into electricity, both Ernst Werner von Siemens and James Clerk Maxwell recognized the importance of this discovery. Following the work of Russell Ohl in the 1940s, researchers Gerald Pearson, Calvin Fuller and Daryl Chapin created the crystalline silicon solar cell in 1954. These early solar cells cost 286 USD/watt and reached efficiencies of 4.56%. By 2012 available efficiencies exceed 20% and the maximum efficiency of research photovoltaics is over 40%.

In the 1880s, who constructed the first solar cell?
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A:
Charles Fritts