How do greenhouses help with temperature control?

Greenhouses help with temperature control primarily by trapping the sun's heat. The structure of a greenhouse typically incorporates transparent materials like glass or plastic that allow sunlight to enter. Once the sunlight penetrates the greenhouse, it warms up the air and surfaces inside. The heat becomes trapped because the transparent materials prevent the warmth from escaping back out into the atmosphere. This creates a warmer environment compared to the outside temperature, which is particularly beneficial for growing plants that thrive in warmer conditions.

In contrast, options related to reflecting sunlight, providing shade, or cooling the air do not contribute to the greenhouse's ability to maintain a higher temperature. Reflecting sunlight would not allow for the warmth to be absorbed, providing shade would reduce the amount of sunlight reaching the plants, and cooling the air contradicts the fundamental purpose of a greenhouse, which is to create a warm, controlled environment for plant growth.