OG详解-OG10 数学1 Q12

Choice B is correct. It′s given that the airplane descends at a constant rate of 400 feet per minute. Since the altitude decreases by a constant amount during each fixed time period, the relationship between the airplane′s altitude and time is linear. Since the airplane descends from an altitude of 9,500 feet to 5,000 feet, the airplane′s altitude is decreasing with time. Thus, the relationship is best modeled by a decreasing linear function.
Choice A is incorrect and may result from conceptual or calculation errors. Choice C is incorrect and may result from conceptual or calculation errors. Choice D is incorrect and may result from conceptual or calculation errors.