B19 or B-19 may refer to:
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B19 (New York City bus)
The Metropolitan Transportation Authority (MTA) operates a number of bus routes in Brooklyn, New York (state), New York, United States; one minor route is privately operated under a city government-granted monopoly, franchise. Many of them are th ...
, serving Brooklyn
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Douglas XB-19
The Douglas XB-19 was a four-engined, piston-driven heavy bomber produced by the Douglas Aircraft Company for the United States Army Air Forces (USAAF) during the early 1940s. It was the largest bomber built for the USAAF until 1946, and was ...
, an experimental bomber aircraft
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Parvovirus B19, the virus that causes fifth disease
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Caro–Kann Defence
The Caro–Kann Defence is a chess opening characterised by the moves:
:1. e4 c6
The Caro–Kann is a common defence against the King's Pawn Opening. It is classified as a Semi-Open Game, like the Sicilian Defence and French Defence, althoug ...
ECO code in chess
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Patient B-19
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Boron-19 (B-19 or
19B), an isotope of boron
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LNER Class B19, classified B2 until 1945
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