Problem: Extract the answer to the question from the following context. Question: Which trains can you take to travel to Boston from Union Station? Context: Union Station is further served by four Amtrak lines: the Northeast Regional and the high-speed Acela Express provide service to New York, Washington, D.C. and Boston, and rank as the first and second busiest routes in the country; the New HavenSpringfield Line provides service to Hartford and Springfield, Massachusetts; and the Vermonter provides service to both Washington, D.C., and Vermont, 15 miles (24 km) from the Canadian border. Amtrak also codeshares with United Airlines for travel to any airport serviced by United Airlines, via Newark Airport (EWR) originating from or terminating at Union Station, (IATA: ZVE).

A: the Northeast Regional and the high-speed Acela Express

Problem: Extract the answer to the question from the following context. Question: What needs to be oscillated in order to create a breathy voice? Context: So-called voiced aspirated consonants are nearly always pronounced instead with breathy voice, a type of phonation or vibration of the vocal folds. The modifier letter after a voiced consonant actually represents a breathy-voiced or murmured dental stop, as with the "voiced aspirated" bilabial stop b in the Indo-Aryan languages. This consonant is therefore more accurately transcribed as b, with the diacritic for breathy voice, or with the modifier letter b, a superscript form of the symbol for the voiced glottal fricative .

A: vocal folds

Problem: Extract the answer to the question from the following context. Question: What BC year did Han forces begin fighting the Xiongnu in order to dominate the oasis city-states in the Tarim Basin? Context: From roughly 115 to 60 BC, Han forces fought the Xiongnu over control of the oasis city-states in the Tarim Basin. Han was eventually victorious and established the Protectorate of the Western Regions in 60 BC, which dealt with the region's defense and foreign affairs. The Han also expanded southward. The naval conquest of Nanyue in 111 BC expanded the Han realm into what are now modern Guangdong, Guangxi, and northern Vietnam. Yunnan was brought into the Han realm with the conquest of the Dian Kingdom in 109 BC, followed by parts of the Korean Peninsula with the colonial establishments of Xuantu Commandery and Lelang Commandery in 108 BC. In China's first known nationwide census taken in 2 AD, the population was registered as having 57,671,400 individuals in 12,366,470 households.

A: 115

Problem: Extract the answer to the question from the following context. Question: This thing, mostly used as a pure metal, is no longer pure when it is needed for? Context: The major applications of copper are in electrical wires (60%), roofing and plumbing (20%) and industrial machinery (15%). Copper is mostly used as a pure metal, but when a higher hardness is required it is combined with other elements to make an alloy (5% of total use) such as brass and bronze. A small part of copper supply is used in production of compounds for nutritional supplements and fungicides in agriculture. Machining of copper is possible, although it is usually necessary to use an alloy for intricate parts to get good machinability characteristics.

A:
intricate parts to get good machinability characteristics