THE CORRECT ANSWER IS (C). IN THE ORIGINAL SENTENCE, THE TWO-WORD...

12. The correct answer is (C). In the original sentence, the two-word phrase some times

is improper in context and should be replaced with a word such as occasionally or

sometimes. Also, the original sentence employs the passive voice—the subject (airplanes

departing) is acted upon by (prevented by) its object (severe weather). The result is

awkward and confusing. Choice (C) corrects both problems, replacing some times with

sometimes and using the active voice instead.