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

Input: Consider Input: What does every plane have?, Context: Grey-box testing (American spelling: gray-box testing) involves having knowledge of internal data structures and algorithms for purposes of designing tests, while executing those tests at the user, or black-box level. The tester is not required to have full access to the software's source code.[not in citation given] Manipulating input data and formatting output do not qualify as grey-box, because the input and output are clearly outside of the "black box" that we are calling the system under test. This distinction is particularly important when conducting integration testing between two modules of code written by two different developers, where only the interfaces are exposed for test.

Output: black box


Input: Consider Input: What did those tapped by those in power have to follow?, Context: The Ming court appointed three Princes of Dharma (法王) and five Princes (王), and granted many other titles, such as Grand State Tutors (大國師) and State Tutors (國師), 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.

Output: the rule of law


Input: Consider Input: What is deeper in the Earth, surface soil or halite?, Context: Underpinning Houston's land surface are unconsolidated clays, clay shales, and poorly cemented sands up to several miles deep. The region's geology developed from river deposits formed from the erosion of the Rocky Mountains. These sediments consist of a series of sands and clays deposited on decaying organic marine matter, that over time, transformed into oil and natural gas. Beneath the layers of sediment is a water-deposited layer of halite, a rock salt. The porous layers were compressed over time and forced upward. As it pushed upward, the salt dragged surrounding sediments into salt dome formations, often trapping oil and gas that seeped from the surrounding porous sands. The thick, rich, sometimes black, surface soil is suitable for rice farming in suburban outskirts where the city continues to grow.


Output: halite