Mrs．Smith was doing the house when she heard someone shouting outside． 1 about her son, she dashed out．What she saw shocked her：Her son Tommy was standing from his armchair, pointing to a cute little dog and 2 excitedly．
If you knew the 3-year-old boy couldn't walk or speak 3 that, you would not wonder why Mrs．Smith was so shocked at the 4 of his son's behavior．Actually, Tommy is a very 5 boy, with golden hair and big blue eyes, but when you talk with him you may find there is something wrong with him：He 6 to make eye contact with you or to respond to you; instead, he murmurs to 7 about something nobody can understand-he lives in a word of his own．
Mrs．Smith found that was a dog next door．He surely 8 the boy．He ran to him and sat before him, his body 9 and his tail wagging．The boy reached his hand to touch the dog's face while the dog licked the boy's hand with his 10 ．Then they began to “talk”, “laugh”, and “walking” on 11 legs around the yard．
Seeing this, tears of 12 filled Mrs．Smith's eyes．Three years before, her husband had 13 her and her son because of her son's illness, and ever since her son had been the 14 of her life．She had taken her son to many experts but with 15 effect．
From then on, the little dog became their 16 visitor and Tommy 17 stepped out of his own world and turned normal boy．
Animals have been 18 of mankind for thousands of years．Man has turned more cunning and less reliable as he has become more 19 , while animals remain pure and innocent, 20 that he feels more comfortable with them than with his fellow creature．