Article: The Romans liked bright colors, and many Roman villas were decorated with vivid red murals. The pigment used for many of the murals was called vermilion, and it came from the mineral cinnabar, a common ore of mercury. It was one of the finest reds of ancient times – the paintings have retained their brightness for more than twenty centuries. The source of cinnabar for the Romans was a group of mines near Almadén, southwest of Madrid, in Spain. Working in the mines was extremely dangerous, since mercury is highly toxic; the miners were slaves or prisoners, and being sent to the cinnabar mines was a virtual death sentence.

Question: What mines did Romans use to acquire cinnabar?
Ans: Almadén, southwest of Madrid, in Spain


Article: The brains of all species are composed primarily of two broad classes of cells: neurons and glial cells. Glial cells (also known as glia or neuroglia) come in several types, and perform a number of critical functions, including structural support, metabolic support, insulation, and guidance of development. Neurons, however, are usually considered the most important cells in the brain. The property that makes neurons unique is their ability to send signals to specific target cells over long distances. They send these signals by means of an axon, which is a thin protoplasmic fiber that extends from the cell body and projects, usually with numerous branches, to other areas, sometimes nearby, sometimes in distant parts of the brain or body. The length of an axon can be extraordinary: for example, if a pyramidal cell, (an excitatory neuron) of the cerebral cortex were magnified so that its cell body became the size of a human body, its axon, equally magnified, would become a cable a few centimeters in diameter, extending more than a kilometer. These axons transmit signals in the form of electrochemical pulses called action potentials, which last less than a thousandth of a second and travel along the axon at speeds of 1–100 meters per second. Some neurons emit action potentials constantly, at rates of 10–100 per second, usually in irregular patterns; other neurons are quiet most of the time, but occasionally emit a burst of action potentials.

Question: Axons send signals that are named what?
Ans: action potentials


Article: Archaeological finds suggest that the area has been inhabited since the stone age. Following the Roman invasion of Britain in AD 43 and the conquering of the local Britons in 70 AD the fortress settlement of Clausentum was established. It was an important trading port and defensive outpost of Winchester, at the site of modern Bitterne Manor. Clausentum was defended by a wall and two ditches and is thought to have contained a bath house. Clausentum was not abandoned until around 410.

Question: What is the site of Clausentum called now?
Ans: Bitterne Manor


Article: Samba Schools are large, social entities with thousands of members and a theme for their song and parade each year. In Rio Carnival, samba schoolsparade in the Sambadrome ("sambódromo" in Portuguese). Some of the most famous include GRES Estação Primeira de Mangueira, GRES Portela, GRES Imperatriz Leopoldinense, GRES Beija-Flor de Nilópolis, GRES Mocidade Independente de Padre Miguel, and recently, Unidos da Tijuca and GRES União da Ilha do Governador. Local tourists pay $500–950, depending on the costume, to buy a Samba costume and dance in the parade. Blocos are small informal groups with a definite theme in their samba, usually satirizing the political situation. About 30 schools in Rio gather hundreds of thousands of participants. More than 440 blocos operate in Rio. Bandas are samba musical bands, also called "street carnival bands", usually formed within a single neighborhood or musical back-ground. The Carnival industry chain amassed in 2012 almost US$1 billion in revenues.

Question: About how many Samba schools are in Rio?
Ans:
30