問題詳情
47. A man is nearsighted and cannot see things clearly beyond 110 cm from his eyes. What is the focallength of the contact lenses that will enable him to see very distant objects clearly?
(A) 50 cm
(B) -50 cm
(C) -110 cm
(D) 110 cm
(E) -30 cm.
參考答案
答案：C
難度：計算中-1
書單：沒有書單，新增