麻疹的科普利克斑的特点是()
A.出血性斑点
B.持续2~3天后消失
C.0.5~1mm大小
D.出现于一侧近第二臼齿颊黏膜上
E.呈簇状,互不融合
参考答案:C
下列各组顺序的排列不正确的是 ( )
A.原子半径:Na<Mg<Al
B.热稳定性:HCl>H2S>PH3
C.酸性强弱:H2SiO4<H2CO3<H2SO4
D.沸点:H2O>H2Se>H2S
—Wow! You've got so many skirts.
—But _______ of them is in fashion now.[ ]
A. all
B. both
C. neither
D. none