题目

－－Hey,look where you are going? －－Oh,I'm terribly sorry.＿＿＿＿＿． A. I'm not noticing        B.I wasn't noticing C. I haven't noticing       D.I don't noticing 答案：B黑暗的房间里有两盏电灯，只有一盏灯点亮，但人能看到未点亮的灯泡。以下对于“看到未点亮灯泡”所画的光路图，正确的是A.  B.  C.  D.