Problem: Glacier:

In glaciated areas where the glacier moves faster than one km per year, glacial earthquakes occur. These are large scale temblors that have seismic magnitudes as high as 6.1. The number of glacial earthquakes in Greenland peaks every year in July, August and September and is increasing over time. In a study using data from January 1993 through October 2005, more events were detected every year since 2002, and twice as many events were recorded in 2005 as there were in any other year. This increase in the numbers of glacial earthquakes in Greenland may be a response to global warming.

What is causing a decrease in Greenlands glacial earthquakes?
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A: unanswerable


Problem: Biodiversity:

The control of associated biodiversity is one of the great agricultural challenges that farmers face. On monoculture farms, the approach is generally to eradicate associated diversity using a suite of biologically destructive pesticides, mechanized tools and transgenic engineering techniques, then to rotate crops. Although some polyculture farmers use the same techniques, they also employ integrated pest management strategies as well as strategies that are more labor-intensive, but generally less dependent on capital, biotechnology and energy.

What is one of the great polyculture challenges that farmers face?
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A: unanswerable


Problem: Valencia:

Valencia was founded as a Roman colony in 138 BC. The city is situated on the banks of the Turia, on the east coast of the Iberian Peninsula, fronting the Gulf of Valencia on the Mediterranean Sea. Its historic centre is one of the largest in Spain, with approximately 169 hectares; this heritage of ancient monuments, views and cultural attractions makes Valencia one of the country's most popular tourist destinations. Major monuments include Valencia Cathedral, the Torres de Serrans, the Torres de Quart, the Llotja de la Seda (declared a World Heritage Site by UNESCO in 1996), and the Ciutat de les Arts i les Ciències (City of Arts and Sciences), an entertainment-based cultural and architectural complex designed by Santiago Calatrava and Félix Candela. The Museu de Belles Arts de València houses a large collection of paintings from the 14th to the 18th centuries, including works by Velázquez, El Greco, and Goya, as well as an important series of engravings by Piranesi. The Institut Valencià d'Art Modern (Valencian Institute of Modern Art) houses both permanent collections and temporary exhibitions of contemporary art and photography.

How big is Valencia's historic centre?
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A: 169 hectares


Problem: Capacitor:

A capacitor consists of two conductors separated by a non-conductive region. The non-conductive region is called the dielectric. In simpler terms, the dielectric is just an electrical insulator. Examples of dielectric media are glass, air, paper, vacuum, and even a semiconductor depletion region chemically identical to the conductors. A capacitor is assumed to be self-contained and isolated, with no net electric charge and no influence from any external electric field. The conductors thus hold equal and opposite charges on their facing surfaces, and the dielectric develops an electric field. In SI units, a capacitance of one farad means that one coulomb of charge on each conductor causes a voltage of one volt across the device.

What type of charges do conductors hold on their facing surfaces?
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A:
equal and opposite charges