题目内容：
Robert is fifteen now. Two and a half years ago he came to the city and began to study in a middle school. He studies hard and gets on well with his classmates. And he often helps his friends with their lessons. But as he comes from a village, the headmaster who was born in a rich family is bad to him and does his best to make excuses to punish him. The boy knows it and takes precautions against(提防) it.One afternoon all the students went to have lunch and he bought a piece of bread. He was reading a book under a big tree, while a dog was standing near him. At that moment the headmaster came out and saw it. He became angry and said, “Don’t you know we don’t let anybody rear (饲养) dogs in the school?”“Yes, I do, sir. ”said the boy.“Why have you brought your dog to school, then?”“It isn’t my dog. ”“Why is it following you, then?”“You’re following me now, sir. ” said the boy, “Can you say you are mine?”请根据以上短文在改写后短文的空白处填入适当的词，使其完整。
Robert is fifteen. He is in Grade _______(1) now. He studies hard and his classmates are _______(2) to him. And he often helps his friends to _______(3) their lessons. But as he was _______(4) in a farmer family, the headmaster from a _______(5) family is bad to him and does_______(6) he can to punish him.One day in the _______(7), all the students went _______(8) lunch and he bought a piece of bread, reading a book under a tree. At the moment a dog was standing near him. _______(9) the headmaster saw this, he wanted to_______(10) him. But he failed that day again.
第6个答案是what,能不能填anything?为什么呢？
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