A:
B:
C:
D:
—Will you please tell us how you can seize the robbers?
—I will spend a whole week ________in your room to wait for their coming.
直角坐标平面内,一点光源位于A(0,5)处,线段CD⊥x轴,D为垂足,C(4,1),则CD在x轴上的影长为 ____ ,点C的影子的坐标为____ .