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Downtown Boston's streets grew organically, so they do not form a planned grid, unlike those in later-developed Back Bay, East Boston, the South End, and South Boston. Boston is the eastern terminus of I-90, which in Massachusetts runs along the Massachusetts Turnpike. The elevated portion of the Central Artery, which carried most of the through traffic in downtown Boston, was replaced with the O'Neill Tunnel during the Big Dig, substantially completed in early 2006.

How did the streets of downtown Boston grow?
Answer: organically
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Current Governor of the Reserve Bank of India Raghuram Rajan had predicted the crisis in 2005 when he became chief economist at the International Monetary Fund.In 2005, at a celebration honouring Alan Greenspan, who was about to retire as chairman of the US Federal Reserve, Rajan delivered a controversial paper that was critical of the financial sector. In that paper, "Has Financial Development Made the World Riskier?", Rajan "argued that disaster might loom." Rajan argued that financial sector managers were encouraged to "take risks that generate severe adverse consequences with small probability but, in return, offer generous compensation the rest of the time. These risks are known as tail risks. But perhaps the most important concern is whether banks will be able to provide liquidity to financial markets so that if the tail risk does materialise, financial positions can be unwound and losses allocated so that the consequences to the real economy are minimised."

What are risks called that generate severe adverse consequences with small probability but generous compensation the rest of the time?
Answer: tail risks
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Traditionally, the first step in most Buddhist schools requires taking refuge in the Three Jewels (Sanskrit: tri-ratna, Pāli: ti-ratana)[web 19] as the foundation of one's religious practice. The practice of taking refuge on behalf of young or even unborn children is mentioned in the Majjhima Nikaya, recognized by most scholars as an early text (cf. Infant baptism). Tibetan Buddhism sometimes adds a fourth refuge, in the lama. In Mahayana, the person who chooses the bodhisattva path makes a vow or pledge, considered the ultimate expression of compassion. In Mahayana, too, the Three Jewels are perceived as possessed of an eternal and unchanging essence and as having an irreversible effect: "The Three Jewels have the quality of excellence. Just as real jewels never change their faculty and goodness, whether praised or reviled, so are the Three Jewels (Refuges), because they have an eternal and immutable essence. These Three Jewels bring a fruition that is changeless, for once one has reached Buddhahood, there is no possibility of falling back to suffering.

What type of Buddhism adds a fourth refuge?
Answer:
Tibetan