Question

Whereas a ramjet generally cannot achieve high speeds without the initial assistance of a rocket, high speeds can be attained by scramjets, or supersonic combustion ramjets, in that they reduce airflow compression at the entrance of the engine and letting air pass through at supersonic speeds.
Which of the following, if true, most seriously weakens the argument?

• A. high speeds can be attained by scramjets, or supersonic combustion ramjets, in that they reduce
• B. that high speeds can be attained by scramjets, or supersonic combustion ramjets, is a result of their reducing
• C. the ability of scramjets, or supersonic combustion ramjets, to achieve high speeds is because they reduce
• D. scramjets, or supersonic combustion ramjets, have the ability of attaining high speeds when reducing
• E. scramjets, or supersonic combustion ramjets, can attain high speeds by reducing

Hint:

Ensure that the subject-verb relationship is direct and unambiguous when explaining mechanisms or processes.

Answer 1

Answer: (E)

Step 1: Analyzing sentence structure.
The sentence needs a logical and clear expression of how high speeds are attained by scramjets. The construction "can attain high speeds by reducing" is the clearest and most accurate.
Step 2: Analyzing the options.
- (A) This option doesn’t clearly express the mechanism of attaining high speeds.
- (B) This weakens the argument because "is a result of their reducing" is overly complex.
- (C) This option is grammatically incorrect.
- (D) This option is awkward and introduces unnecessary complexity.
- (E) This is the correct answer because it clearly and concisely describes how scramjets attain high speeds.
Step 3: Conclusion.
The correct answer is (E), as it is clear and grammatically correct.