When I was young,I spent my summer vacations on my grandparents' farm.The summer that I graduated from college,I (56)my grandparents once again.When I arrived, I discovered that there was a family(57)in progress. Grandpa's dog and hunting partner, Rusty,had taken on a very bad(58)in his old age.He had begun(59)into the chicken coop（鸡笼）and eating eggs.In the eyes of the local farmers,(60) dogs started stealing eggs,there was no(61)to cure them.They knew there was only one thing to be done(62)such a dog—you had to shoot it and the sooner the (63). Rusty and Grandpa were old friends.Grandpa certainly didn't (64)to shoot Rusty, but he knew it needed to be done.The "egg money"was Grandma's private income,so you can imagine  (65)she felt about the problem.(66)the inexperienced confidence of youth,I told Grandpa that I thought I could “cure”the egg-stealing dog.I wanted to at least have a(67)to save Rusty's life,and save Grandpa from the sadness of(68)Rusty. The next morning,I broke open six flesh eggs and put them in Rusty's bowl(69)at the door to the chicken coop.Rusty came(70)and noticed the eggs.He quickly(71)the eggs and happily walked off for his nap（打盹）.The following morning I did the (72) thing. I put the eggs a few feet away from the chicken coop, toward the back door of the farmhouse (73)Grandma usually fed Rusty.The next day I again moved the bowl closer to the house, and added some dog food to the eggs.Every day I moved the bowl closer to the back door,mixing more dog food and (74) eggs.By the time the bowl reached the door,it was all dog food and no eggs.Rusty had again become (75)  to looking for his food at the back door of the house,and never again went into the chicken coop.