question: nearsightedness:farsightedness
choices.label: A B C D
choices.text: rain:hail thin:obese forward:backward contraction:relaxation
explanation: both "nearsightedness" and "farsightedness" refer to abnormal states of vision. "rain" and "hail" are both weather phenomena. both "thin" and "obese" refer to abnormal states of body shape. both "forward" and "backward" cannot indicate some abnormal state. the opposite of "contract" is to expand, not "relaxation".