下列离子方程式中正确的是( ) A．用FeCl3溶液腐蚀铜制印刷电路板：Fe3＋

发布时间：2017-06-25 01:07 │ 来源：www.tikuol.com

题型：选择题

问题：

下列离子方程式中正确的是(　　)

A．用FeCl₃溶液腐蚀铜制印刷电路板：Fe³^＋＋Cu=Fe²^＋＋Cu²^＋

B．NH₄HCO₃溶液和过量的NaOH溶液相混合：HCO₃^—＋OH^－=CO₃²^—＋H₂O

C．向Fe₂(SO₄)₃的酸性溶液中通入足量H₂S：Fe³^＋＋H₂S=FeS↓＋2H^＋

D．FeI₂溶液中通入Cl₂至I^－恰好完全被氧化：2I^－＋Cl₂=I₂＋2Cl^－

考点：氧化铁单质铁碱式碳酸铜氧化铜

题型：选择题

根据对话内容，选择恰当的句子补全下列对话。

A: Hi, Mike! Can you tell me something about Siberian(西伯利亚) tigers?
B: Of course.?
A:       1        .
B: They are big and strong. They have bright eyes，yellow fur(皮毛) and black stripes(条纹).
A: Can they climb trees?
B:      2       But they can run very fast and are good at hunting(猎取) other animals.
A: How do they usually live?
B: They usually live as a family until the baby tigers are two or three years old.
A:      3
B: About two to four. They look lovely at birth.(出生时)?
A: So wonderful!        4
B: But the number of tigers is getting smaller and smaller.?
A: What? How many Siberian tigers are there in the world?
B:      5       There are fewer and fewer Siberian tigers because people hunt them for their fur and bones.
A: Yes, I think so. Let’s do something to protect Siberian tigers.

A. No, they can’t.?
B. What’s your favorite animal?
C. I hope I can see one of them.?
D. What do they look like?
E. About four hundred.?
F. What do they like doing?
G. How many baby tigers can they have at a time?

查看答案

题型：选择题

Only when _______ 30 years old ______ to learn English.

A．was he; did he begin

B．he was; he began

C．he was; did he begin

D．was he; he began

查看答案

题型：选择题

职业安全健康管理体系审核分为( )两种基本类型。

A．第一现场和第二现场

B．第一阶段和第二阶段

C．内部审核和外部审核

D．第一阶段和现场

查看答案

题型：选择题

临床上对肝硬化伴有高血氨患者禁用肥皂液灌肠，这是因为

A．肥皂液致肠道pH升高，促进氨的吸收

B．可能导致碱中毒

C．可能严重损害肾脏功能

D．肥皂液促进肠道细菌的腐败作用

查看答案

题型：选择题

在IP包头中包括（）。

A、远地址

B、目的地址

C、源和目的地址

D、在IP包头中没有地址

查看答案

更多题库