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举一反三
【单选题】Ladies and gentlemen, welcome to Dalian, a famous summer resort ( 避暑胜地 ) and one of the best tourist cities in China. With clear sky, green mountains, blue seas, fine beaches, clean streets and lovely...
A.
comes in the best season.
B.
is here to join more tourists
C.
may not stand the heat here.
D.
is traveling back home.
【单选题】每一吨铸铁成本y（元）随铸铁废品率x（％）变动的回归方程为y=56+8x，这意味着（）
A.
废品率每增加1％，成本每吨增加64元
B.
废品率每增加1％，成本每吨增加8％
C.
废品率每增加1％，成本每吨增加8元
D.
废品率每增加1％，成本每吨为56元