問題詳情

18.A phase of the characteristic of a flashing light during which the light is not exhitited defines__________ .
(A)directional area
(B) eclipse
(C)faint sector
(D)unintensified sector

參考答案

答案：B
難度：適中0.666667
統計：A(0),B(2),C(0),D(1),E(0)