GRE Text Completion: OG/PP2-GRE填空OG/PP2 - I1ILTE0UXO96128IF

The spy's repeated bungling was, above all else, ____________ those who wished to thwart her efforts, since it was so unpredictable as to obscure any pattern that might otherwise lead to her capture. A. an obstacle to B. a signal to C. a hindrance to D. an indication for E. a snare for F. a boon to