能在溶液中大量共存，加入（NH4）2Fe（SO4）2-6H2O晶体后仍能大量存在

发布时间：2017-05-05 17:21 │ 来源：www.tikuol.com

题型：选择题

问题：

能在溶液中大量共存，加入（NH₄）₂Fe（SO₄）₂-6H₂O晶体后仍能大量存在的离子组是（　　）

A．Na⁺、H⁺、Cl^-、NO₃^-

B．K⁺、Ba²⁺、OH^-、I^-

C．Na⁺、Mg²⁺、Cl^-、SO₄^2-

D．Cu²⁺、S^2-、Br^-、ClO^-

考点：离子共存

题型：选择题

阅读理解。

          When I was at university I studied very hard. But a lot of my friends did very little work. Some did just
enough to pass exams. Others didn't do quite enough. Fred Baines was one of them. He spent more time drinking
in the Students' Union than working in the library.
          Once, at the end of the term, we had to take an important test in chemistry. The test had a hundred
questions. Beside each question we had to write "True" or "False". While I was studying in my room the night
before the test, Fred was watching television. Fred usually worried a lot the night before a test. But on that night
he looked perfectly calm. Then he told me of his plan.
          "It's very simple. There are a hundred questions and I have to get fifty correct to pass the test. I'll take a
coin into the examination room. I haven't studied a chemistry book for months, so I'll just toss the coin. (throw
the coin into the air.) That way, I'm sure I'll get half the questions right."
          The next day, Fred came happily into the examination room. As he sat tossing a coin for half an hour he
marked down his answers. Then he left, half an hour before the rest of us.
         The next day, he saw the chemistry professor at the gate.
        "Oh good,"he said,"Have you got the results of the test?"
         The professor looked at him and smiled.
         "Ah, it's you, Baines. Just a minute."
          Then he reached into his pocket and took out a coin. He threw it into the air, caught it in his hand and
looked at it.
          "I'm terribly sorry, Baines," he said, "You failed!"

1. Fred Baines usually _____ exams.

Ａ: didn't do
Ｂ: passed
Ｃ: did just enough to pass
Ｄ: failed in

2. Before the chemistry test Fred was ____ Calm.

Ａ: usually
Ｂ: normally
Ｃ: unusually
Ｄ: naturally

3. He was going to toss a coin _____ he answered each question.

Ａ: before
Ｂ: if
Ｃ: after
Ｄ: because

4. The rest of the class_____.

Ａ: answered the questions in half an hour
Ｂ: left half an hour earlier
Ｃ: needed an extra hour
Ｄ: worked for an hour

5. The chemistry professor_____.

Ａ: didn't mark the test papers correctly
Ｂ: tossed a coin when he marked test papers
Ｃ: knew about Fred's method (方法)
Ｄ: thought Fred's method was good

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题型：选择题

从基础货币的来源来看，它是指货币当局的（）。

A.资产

B.负债

C.所有者权益

D.利润

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下列哪项不是HIV主要传播途径（）

A.异性不洁性行为

B.同性性行为

C.共餐共宿

D.静脉内吸毒

E.母婴传播

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题型：选择题

刺激胃黏膜，反射性引起呼吸道腺体分泌的药物是（）。

A.氯化氨

B.乙酰半胱氨酸

C.溴乙新

D.胰蛋白酶

E.脱氧核糖核酸酶

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题型：选择题

为COM1保留的地址是（）。

A.2E8

B.3E8

C.2F8

D.3F8

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