(A) that no less than a technical or scientific breakthrough is necessary
(B) that nothing other than a technical or scientific breakthrough is needed
(C) that a technical or scientific breakthrough is necessary
(D) the necessity for an occurrence of a technical or scientific breakthrough
(E) the necessity for a technical or scientific breakthrough occurring
Solution:
Pronouns + Redundancy
OG Solution:
C is the best choice. The word that functions grammatically to introduce the clause that describes the point that champions of solar cells concede. Choices A and B needlessly lengthen the statement by expressing the idea through negation: no less than and nothing other than could be dropped without loss of meaning. In D and E, the preposition/or is less idiomatic than o/in expressing necessity. Furthermore, both choices present an awkward and wordy noun-plus-prepositional phrase instead of a that clause that would express meaning more exactly and concisely.
Sentence Correction - 1000 Questions with Solution:
