搜题请搜索小程序“爱下问搜题”
问题 选择题

下列物质的鉴别方法错误的是 [ ]

A．用肥皂水鉴别硬水和软水

B．用加热的方法鉴别氯酸钾和氯化钾

C．用带火星的木条鉴别CO2、H2和O2

D．用澄清的石灰水鉴别N2和CO2

答案

答案：C

材料分析题

某市新的中小学生守则和日常行为规范，将原来的“遇到坏人坏事要主动报告、见义勇为、敢于斗争”改为“遇到坏人坏事要主动报告”，“遇到有侵害敢于斗争，善于斗争”，学会“自护自救”等内容。为什么中小学生在遇到侵害时，要学会自护自救？

                                                                                                                                                                

                                                                                                                                                                

                                                                                                                                                                

                                                                                                                                                                

                                                                                                                                                               
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单项选择题 A1型题

蜘蛛痣罕见的分布部位是（）

A.手背

B.前胸

C.上臂

D.下肢

E.面颊部
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