搜题请搜索小程序“爱下问搜题”
问题 选择题

下列离子方程式中错误的是                                           

A．铁跟稀硫酸反应 Fe+2H+=Fe2++H2↑

B．碳酸氢钠溶液与稀盐酸反应2H++CO32― =H2O+CO2↑

C．醋酸与氢氧化钾溶液 CH3COOH+OH－=CH3COO―+H2O

D．碳酸镁跟硫酸反应 MgCO3+2H+=Mg2++H2O+CO2↑

答案

答案：B

A 正确

B 错误，碳酸氢钠电离出碳酸氢根离子和钠离子

C 正确，醋酸是弱电解质，写分子形式

D 正确，碳酸镁不溶于水，写分子形式

故选B

补全对话，情景问答
根据对话情景选择恰当的选项，其中有两项是多余的。
A. I'm sorry to hear that.
B. I hope everything goes well.
C. Your uncle telephoned.
D. Everything is ready.
E. Not so well.
F. He feels very lonely.
G. He has a bad cold.
Mother: Lin Tao, are you setting the table for your grandparents and uncle?
Lin Tao: Yes, Mom. 1.            
Mother: Just set two places. 2.            He said he wasn't able to come.
Lin Tao: What's the matter with him?
Mother: 3.           
Lin Tao: 4.            Did my uncle sound worried?
Mother: Yes. He said he would go to see a doctor.
Lin Tao: 5.            I will ring him up.
查看答案
选择题

在网络高速发展的今天，少数人为了达到个人企图，经常在网上窃取他人电子邮件。这种行为侵犯了公民的

                                                                                                                                                          [ ]

A．荣誉权      

B．名誉权       

C．人身自由权      

D．通信自由和通信秘密权
查看答案