The word that completes the sentence is limiting factor in photosynthesis.
The three limiting elements of photosynthesis for the generation of glucose are temperature, light intensity, and carbon dioxide level, all of which are adjustable in a greenhouse.
A variable that alters the outcome of a process or a chemical reaction is referred to as a limiting factor. Every process has its own constraints that cause changes. We may thus draw the conclusion that the limiting parameters for photosynthesis are temperature, light intensity, and carbon dioxide level.
The modern greenhouse is often a framed glass or plastic enclosure used to grow fruits, vegetables, flowers, and any other plants that need specialized temperature conditions.
Poe's narrator descends into madness early on in the story and from then on, he experiences psychological turbulence that results in the murder of his wife and his own imprisonment for life.
