Scientists generally agree that Earth is getting warmer due to what's called the greenhouse effect. A
greenhouse used for plants stays warm because sunlight and heat coming through the glass roof are mostly
trapped. The heat doesn't radiate back into the atmosphere because it's partly trapped by the glass.
Something like that happens on Earth. The atmosphere acts like a blanket that keeps the Sun's heat from
leaking away into space.
18. In the first sentence, the phrase what's called the greenhouse effect presents a/an
A. effect.
B. illustration.
C. bias.
D. cause.
"due to" is misused in that sentence. The phrase "because of" is far better. So if you read the sentence making that substitution, what choice will you make?
The correct answer to the question is A. effect.
In the given sentence, the phrase "what's called the greenhouse effect" is used to introduce and explain the concept being discussed. It refers to a specific phenomenon, which is the warming of Earth's surface due to the trapping of heat by certain gases in the atmosphere. The phrase "the greenhouse effect" represents the effect itself, not the cause, illustration, or bias.