Extract the answer to the question from the following context. Question: Why did Walpole pack his friends into the House of Commons? Context: From 1721 this was the Whig politician Robert Walpole, who held office for twenty-one years. Walpole chaired cabinet meetings, appointed all the other ministers, dispensed the royal patronage and packed the House of Commons with his supporters. Under Walpole, the doctrine of cabinet solidarity developed. Walpole required that no minister other than himself have private dealings with the king, and also that when the cabinet had agreed on a policy, all ministers must defend it in public, or resign. As a later prime minister, Lord Melbourne, said, "It matters not what we say, gentlemen, so long as we all say the same thing."
----
Answer: cabinet solidarity

Extract the answer to the question from the following context. Question: Who was Zipoetes' son? Context: The Bithynians were a Thracian people living in northwest Anatolia. After Alexander's conquests the region of Bithynia came under the rule of the native king Bas, who defeated Calas, a general of Alexander the Great, and maintained the independence of Bithynia. His son, Zipoetes I of Bithynia maintained this autonomy against Lysimachus and Seleucus I, and assumed the title of king (basileus) in 297 BCE. His son and successor, Nicomedes I, founded Nicomedia, which soon rose to great prosperity, and during his long reign (c. 278 c. 255 BCE), as well as those of his successors, the kingdom of Bithynia held a considerable place among the minor monarchies of Anatolia. Nicomedes also invited the Celtic Galatians into Anatolia as mercenaries, and they later turned on his son Prusias I, who defeated them in battle. Their last king, Nicomedes IV, was unable to maintain himself against Mithridates VI of Pontus, and, after being restored to his throne by the Roman Senate, he bequeathed his kingdom by will to the Roman republic (74 BCE).
----
Answer: Nicomedes

Extract the answer to the question from the following context. Question: What line is international? 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).
----
Answer:
Vermonter