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【简答题】
某炼铁厂的铁水每炉含碳量在正常情况下服从正态分布N(4.55，0.108 2 )，现在抽测5炉铁水，含碳量分别是 4.38 4.45 4.47 4.52 4.50 假如方差没有变化，问在显著性水平α=0.05下所炼铁水的平均含碳量是否有显著变化?
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【简答题】A．He was thinking of the money he could have. B．He could not see very well. C．Pulling in the chain was hard work. D．The bottom of the boat was covered by the golden chain.
【单选题】The sentence “ He could not sleep for noise without and fever within ” in paragraph 4 means “ HE could not sleep because . ”
A.
it was noisy outside and he had a fever
B.
it was quiet inside the hotel and he had a fever
C.
the hotel was so noisy that he became very excited
【单选题】Still, he could not help thinking that if anything______, the nearest person he could contact by radio, if there was a ship nearby, would be on an island 885 miles away.
A.
were happening
B.
should happen
C.
would happen
D.
had happened
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