阅读下面短文，从短文后各题所给的四个选项（A、B、C、D）中，选出可以填入空白处的最佳选项
My previous home had a stand of woods behind it and many animals in the backyard. That first year, I1 feeding peanuts to the blue jays, then the squirrels. The squirrels had no2 coming up right to me for them. As the months went by, the rabbits saw that I was no 3and didn't escape. When I threw carrot slices(薄片)，they even came for a nibble(啃).Slowly they came to4 me, and by the end of the year they were eating out of my hand.
That second year, the rabbits5 me, and one would even sit up for slices! While I was feeding them, I 6 that a groundhog who used to run away was now taking an7interest in this food situation. I carefully extended a long8, with a keen eye on those teeth, and 9,there were times I would have the groundhog sitting next to a rabbit, both munching(津津有味的咀嚼) on carrots. A few months later, while 10,she would even turn her back to me.11when she was facing away, I reached out and 12scratched（搔）her back with my finger, She didn't move.
By year three, the rabbits and the groundhog were back. The groundhog 13didn't have a problem with me scratching her back, and I got an idea, I'd always14,while slicing up carrots, that the end looked like a cap.15one day, just to see what she would do ,I gently 16 one on top of the groundhog's head. Again, not a 17,The next time, I had my camera ready to record what you see here, one of several dozen such pictures,18she had a slice to eat, she never 19 the one of her head. It was a fair 20 —I got a pleasure, and she had yet another tasty treat.