What do you want to do? [ ]
A. I want to play ping-pong.
B. Time for supper.
答案:A
检影距离为50em,此距离检影时恰好为中和,则被检眼的屈光度为
A.-5.00D
B.-2.50D
C.-2.00D
D.-1.50D
E.-1.00D
酸性岩石的粗集料用于高速公路时,宜使用针入度()的沥青。
A.较小
B.较大
C.与针入度无关