()是煤中主要元素之一。它在煤中存在的总量和形态直接影响着煤的性质。
A、碳
B、氢
C、氧
D、氮
参考答案:C
下列说法中不正确的是
A.在标准状况下22.4LH2中含有的氢分子的个数为NA
B.1L1mol/L的KClO3溶液中含有的Cl-个数为NA
C.凡是溶于水能导电的化合物就是电解质
D.某溶液中滴加烧碱溶液,加热产生能使湿润的红色石蕊试纸变蓝的气体,则原溶液中一定存在NH4+
This reflects the priority being attached to economic over political activity, partly caused by a growing reluctance to enter a calling blighted by relentless publicity that all too often ends in destroying careers and reputations.
A.powerfulness
B.unwillingness
C.renaissance
D.apologeticness