【单选题】The key _____ locking the classroom door. [ ]
【单选题】This problem ______ discussion. A.is used for B.is up for
【简答题】A.It is used as a tea container. B.It is used to add sugar. C.It is used for measuring tea. D.It is used for mixing tea.
【单选题】测得空气温度直减率为 0.85 °C /100m ,则可断定该气层为:
【单选题】从样本得到变量 X 与 Y 的相关系数 r =0.92, 则
B.
若对此份资料作回归分析 , 其回归系数是正值
C.
若对此份资料作回归分析 , 其回归系数是负值
【单选题】Metal _____ making machines and many other things. [ ]
【单选题】一大出血患者,下列哪项提示该患者病情危重: