In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

Q: What can a tree produce after it is mature?, Context: Different pieces of wood cut from a large tree may differ decidedly, particularly if the tree is big and mature. In some trees, the wood laid on late in the life of a tree is softer, lighter, weaker, and more even-textured than that produced earlier, but in other trees, the reverse applies. This may or may not correspond to heartwood and sapwood. In a large log the sapwood, because of the time in the life of the tree when it was grown, may be inferior in hardness, strength, and toughness to equally sound heartwood from the same log. In a smaller tree, the reverse may be true.

A: wood
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Q: Who ruled Bithynia before Bas?, 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).

A: Calas
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Q: Who set up the leaders of the important schools of Buddhism?, Context: The Ming court appointed three Princes of Dharma () and five Princes (), and granted many other titles, such as Grand State Tutors () and State Tutors (), to the important schools of Tibetan Buddhism, including the Karma Kagyu, Sakya, and Gelug. According to Wang Jiawei and Nyima Gyaincain, leading officials of these organs were all appointed by the central government and were subject to the rule of law. Yet Van Praag describes the distinct and long-lasting Tibetan law code established by the Phagmodru ruler Tai Situ Changchub Gyaltsen as one of many reforms to revive old Imperial Tibetan traditions.

A:
the central government
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