Bunuel
An uncommon method of home building relies on the construction of extremely thick walls to reduce the energy needs due to heating and cooling; the resulting building, with
internal spaces that maintain a constant temperature although the outside air that flows through them varies in temperature, are known as "earth ships."A. internal spaces that maintain a constant temperature although the outside air that flows through them varies in temperature, are known as "earth ships."
B. internal spaces that maintain a constant temperature although they are supplied by varying temperatures of outside air, are known as "earth ships."
C. internal spaces that maintain a constant temperature although the outside air that flows through them varies in temperature, is known as an "earth ship."
D. constant temperature internal spaces although the outside air that flows through them varies in temperature, are known as "earth ships."
E. internal spaces that maintain a constant temperature although they are supplied by varying temperatures of outside air, is known as an "earth ship."
PRINCETON REVIEW OFFICIAL EXPLANATION:
C
This sentence contains a problem in subject/verb agreement. The subject, building, is singular, so it needs a singular verb, is known. You can eliminate (A), (B), and (D).
(A) No. The verb should be is known as.
(B) No. This contains the same subject/verb agreement error as (A). Eliminate it.
(C) Yes. A little clunky, but this choice fixes the stem’s subject/ verb problem.
(D) No. This choice contains the original error of are known. Also, the first four words of this choice are very awkward. Temperature should not be used as an adjective to describe spaces.
(E) No. This choice changes the meaning of the sentence. The interval spaces are not supplied with temperatures. Air flows through them. Eliminate this answer choice.