The date for the conference we had been looking forward ______ at last.
A：to come
B：to coming
C：to came
D：to will come
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____ ．
