A. the ice can easily just slip into the ocean B. volcanoes caused the ice to melt C. melting just in the Northern hemisphere would have been impossible D. researchers often use the computer models to help their research work 参考答案:C 答案解析:[解析] 根据Studies suggest that melting just in the Southern hemisphere Would have been impossible,too可知
第14题: [单项选择]某车间AB、BC相电焊机均为47kW,功率因数为0.6,负载持续率为60%;需要系数为0.5;C相照明共6kW,功率因数为0.9,需要系数为0.9;冷加工机床共420kW,功率因数为0.5,需要系数为0.14;通风机共80kW,功率因数为0.8,需要系数为0.8;回答下列问题:C相照明负荷设备容量为()kW。 A. 6 B. 5.4 C. 3.24 D. 2.6 参考答案:A