从A、B、C、D四个选项中,选出可以填入空白处的最佳选项。
1. —Look! You look so tired after you have climbed that high mountain, but why?
   —_____ the beautiful scenery at the top of it. 
   A. See      B. To see       C. Seeing       D. For seen
2. Generally speaking, the electric bike is not dangerous as _____, if _____ according to the instructions. 
   A. reported; ridden        B. reported; riding   
   C. report; to ride         D. reporting; to be ridden