Question

The following question presents a sentence, part or all of which is underlined. Select the answer that produces the most effective sentence; your answer should make the sentence clear, exact, and free of grammatical error. It should also minimize awkwardness, ambiguity, and redundancy.

EI Nino, the periodic abnormal warming of the sea surface off Peru, a phenomenon in which changes in the ocean and atmosphere combine allowing the warm water that has accumulated in the western Pacific to flow back to the east.

• A. A phenomenon in which changes in the ocean and atmosphere combine allowing the warm water that has accumulated
• B. A phenomenon where changes in the ocean and atmosphere are combining to allow the warm water that is accumulating
• C. A phenomenon in which ocean and atmosphere changes combine and which allows the warm water that is accumulated
• D. Is a phenomenon in which changes in the ocean and atmosphere combine to allow the warm water that has accumulated
• E. Is a phenomenon where ocean and atmosphere changes are combining and allow the warm water accumulating

Answer 1

The correct option is D Is a phenomenon in which changes in the ocean and atmosphere combine to allow the warm water that has accumulated

This accumulation of phrases and clauses results in a sentence fragment; there is no main verb. This problem is easily solved by inserting the verb to be: El Nino . .. is a phenomenon. '" The clause defining phenomenon is clear (in which changes in the ocean and atmosphere combine), but the subsequent phrase, allowing . .. is not. If the participial phrase were to modify the previous clause, a comma would have to be inserted between combine and allowing. A better choice would be to follow combine with to allow, showing purpose. In this sense, the environmental changes combine (intransitive) in order to allow the water to flow back east.

The addition of is completes the sentence; combine to allow shows the purpose of the changes.