Before revision:  To fill this important gap, we construct AdvRACE (Adversarial RACE), a new model-agnostic benchmark for evaluating the robustness of MRC models under six different types of test-time perturbations , including our novel superimposed attack and distractor construction attack .
After revision:  To fill this important gap, we construct AdvRACE (Adversarial RACE), a new model-agnostic benchmark for evaluating the robustness of MRC models under four different types of test-time perturbations , including our novel superimposed attack and distractor construction attack .