Mom and Dad arrived back from vacation a day earlier 小题1:_______ expected. They could 小题2: _______ wait to surprise the boys but found the house was in a mess with garbage all over the places. Their dog, Spot, was tired 小题3:_______ hungry. But the money for dog food was gone. So they shouted at their elder son Daniel. Daniel felt angry 小题4:__________ he wasn’t given a chance to tell the truth.
In fact, 小题5:_________ their parents were away from home, their dog fell ill. The boys used the money to take it to the hospital and they had no time to clean the house.
Daniel shouted and ran into小题6:_______ bedroom. He shut the door angrily. Daniel’s younger brother Eric advised him to explain everything to their parents. Daniel didn’t think they deserved an explanation, saying that why they didn’t ask him what happened instead of shouting at him.
Mom felt that there may be a reason 小题7:______ the house was a mess and they may be too hard on Daniel. 小题8:_______, Dad said that Daniel was too rude and should be punished.
，S2，则可以作出服从自由度为n的χ2分布的随机变量
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