THE CORRECT ANSWER IS (D). IN THE ORIGINAL SENTENCE, TWO MAIN CLAU...

12. The correct answer is (D). In the original sentence, two main clauses are incorrectly

separated only by a comma, without an appropriate connecting word after the comma.

Choice (D) inserts the word and, which makes sense in context—providing an

appropriate rhetorical balance between the ideas in the two clauses. Although their

levels of radiation is a bit wordier than radiation levels, the phrase is clear and

grammatically correct.

550

PART VI: Five Practice Tests