A:who was charged by speeding
B:who accused him of speeding
C:which was warned of speeding
D:whom reminded him to speed
平面直角坐标系中,点(﹣2,4)关于x轴的对称点在( )
据一项专项调查表明,有不少学生有过被校内外不法分子敲诈、勒索、抢劫、搜身、欺侮及其他滋扰的经历。假如你遇到类似的情况,你应该( )
下列粒子的符号或物质的化学式书写不正确的有( )
①氮气N2②氧化锌ZnO③硫酸铁FeSO4④氯化钠NaCl⑤汞离子Hg+⑥碳酸氢钠Na2HCO3⑦锰酸钾KMnO4.