For hot desert locations with access to seawater, a new greenhouse design generates freshwater and cool air. Oriented to the pre

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问题 For hot desert locations with access to seawater, a new greenhouse design generates freshwater and cool air. Oriented to the prevailing wind, the front wall of perforated cardboard, moistened and cooled by a trickle of seawater pumped in, cools and moistens hot air blowing in. This cool, humidified air accelerates plant growth; little water evaporates from leaves. Though greenhouses normally capture the heat of sunlight, a double-layered roof, the inner layer coated to reflect infrared light outward, allows visible sunlight in but traps solar heat between the two layers. This heated air, drawn down from the roof, then mixes with the greenhouse air as it reaches a second seawater-moistened cardboard wall at the back of the greenhouse. There the air absorbs more moisture, which then condenses on a metal wall cooled by seawater, and thus distilled water for irrigating the plants collects.
It can be inferred that the process described in the passage makes use of which of the following?

选项 A、The tendency of hot air to rise
B、The directional movement of wind
C、The temperature differential between the sea and the desert

答案B

解析 Choices B and C are correct. This question asks the reader which of the three phenomena listed in the answer choices is used in the process described in the passage.
Choice A is incorrect: the passage does not indicate that the tendency of hot air to rise is used in the process, and in fact says that heated air is drawn down, not up, as part of the greenhouse design.
Choice B is correct: the second sentence describes the orientation of a perforated cardboard wall toward the prevailing wind so that hot air blows in and is moistened.
Choice C is correct: the passage describes the use of seawater to cool hot desert air and to provide moisture that is absorbed by heated air and then condensed on a seawater-cooled surface for the purpose of irrigating the plants.
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