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There are several types of multi-color white LEDs: di-, tri-, and tetrachromatic white LEDs. Several key factors that play among these different methods, include color stability, color rendering capability, and luminous efficacy. Often, higher efficiency will mean lower color rendering, presenting a trade-off between the luminous efficacy and color rendering. For example, the dichromatic white LEDs have the best luminous efficacy (120 lm/W), but the lowest color rendering capability. However, although tetrachromatic white LEDs have excellent color rendering capability, they often have poor luminous efficacy. Trichromatic white LEDs are in between, having both good luminous efficacy (>70 lm/W) and fair color rendering capability.
 What type has the worst luminous efficacy?
A: unanswerable

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The event was significant not only for Yugoslavia and Tito, but also for the global development of socialism, since it was the first major split between Communist states, casting doubt on Comintern's claims for socialism to be a unified force that would eventually control the whole world, as Tito became the first (and the only successful) socialist leader to defy Stalin's leadership in the COMINFORM. This rift with the Soviet Union brought Tito much international recognition, but also triggered a period of instability often referred to as the Informbiro period. Tito's form of communism was labeled "Titoism" by Moscow, which encouraged purges against suspected "Titoites'" throughout the Eastern bloc.
Who became the first leader to defy Stalin's leadership?
A: Tito

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Between 1631 and 1890, the city tripled its area through land reclamation by filling in marshes, mud flats, and gaps between wharves along the waterfront. The largest reclamation efforts took place during the 19th century; beginning in 1807, the crown of Beacon Hill was used to fill in a 50-acre (20 ha) mill pond that later became the Haymarket Square area. The present-day State House sits atop this lowered Beacon Hill. Reclamation projects in the middle of the century created significant parts of the South End, the West End, the Financial District, and Chinatown. After The Great Boston Fire of 1872, workers used building rubble as landfill along the downtown waterfront. During the mid-to-late 19th century, workers filled almost 600 acres (2.4 km2) of brackish Charles River marshlands west of Boston Common with gravel brought by rail from the hills of Needham Heights. The city annexed the adjacent towns of South Boston (1804), East Boston (1836), Roxbury (1868), Dorchester (including present day Mattapan and a portion of South Boston) (1870), Brighton (including present day Allston) (1874), West Roxbury (including present day Jamaica Plain and Roslindale) (1874), Charlestown (1874), and Hyde Park (1912). Other proposals, for the annexation of Brookline, Cambridge, and Chelsea, were unsuccessful.
What famous disaster happened in Boston in 1872?
A: The Great Boston Fire of 1872

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In the early 20th century, the vast conscription of Italian men from all throughout Italy during World War I is credited with facilitating the diffusion of standard Italian among less educated Italian men, as these men from various regions with various regional languages were forced to communicate with each other in a common tongue while serving in the Italian military. With the eventual spread of the radio and television throughout Italy and the establishment of public education, Italians from all regions were increasingly exposed to standard Italian, while literacy rates among all social classes improved. Today, the majority of Italians are able to speak standard Italian, though many Italians still speak their regional language regularly or as their primary day-to-day language, especially at home with family or when communicating with Italians from the same town or region. However, to some Italians, speaking a regional language, especially in a formal setting or outside of one's region, may carry a stigma or negative connotations associated with being lower class, uneducated, boorish, or overly informal.
What is never associated with being overly informal?
A:
unanswerable