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2003年诺贝尔化学奖授予美国科学家Peter Agre和Roderick Mackinnon以表彰他们在“水通道”和“离子通道”的研究成果。Mackinnon教授的研究内容主要是Na、K虽然体积很接近，但在生物体内呈现的差别却高达1万倍，他让科学家们观测到Na、K在进入离子通道前、通道中以及穿过通道后的状态，在医学应用上可为病人在“离子通道”中寻找具体的病因，并研制相应药物。下列关于钠、钾的说法正确的是（ ）

A．质钠的密度比钾的密度小

B．和钾在空气中燃烧的产物都是过氧化物

C．一小块钠投入盛5 mL澄清石灰水的试管里，可能观察到溶液变浑浊

D．和钾的合金〔w(K)=50%～80%〕熔点比钠和钾都高

答案

答案：C

本题以诺贝尔化学奖获得者的研究成果为背景命题，考查了金属钠、钾的性质和用途（新考纲增加知识点）及溶解度变化等知识点。详细的解答过程为：碱金属的密度总体上随原子序数增大而增大，但钠的密度反常（比钾大）；钠在空气中燃烧的产物是过氧化钠，但钾在空气中燃烧的产物中还有超氧化钾；将钠投入澄清石灰水中会和水发生反应且放出热量，若石灰水是饱和的（氢氧化钙的溶解度随温度升高而减小），则会有少量Ca(OH)2析出来。

阅读理解
阅读理解。
     Mother's Day and Father's Day are two big national. holidays in many western countries. And it's
interesting because they are not the same in every country. In England, Mothering Sunday is in March.
In America and Germany and other countries, it's one Sunday in May. Father's Day is in the middle of
June. How do you celebrate Mother's Day and Father's Day? Let's learn something more about it from
the following introduction.
        In England, we call Mother's Day Mothering Sunday, because it's always on a
Sunday. I don't really know the origin of it but I remember that my mother had a
cup of tea early in the morning. And then we would go to church. And at the end
of the church service, the children would collect a daffodil (水仙花) and take it
back and give it to our mother who would normally be sitting in the service in the
church. And really that's all we did to celebrate the day.
          As Ann said, I remember taking cups of tea to my mother. The idea in general is
that the washing-up would be done; perhaps some cooking would be done on Mother's
Day. We would try to relieve her of all those jobs to make it a special day for her, so
that whenever she looked around, there was something to eat, something to drink, or
something to read, or something interesting for her to do.
     As Ann said, I remember taking cups of tea to my mother. The idea in general
is that the washing-up would be done; perhaps some cooking would be done on
Mother's Day. We would try to relieve her of all those jobs to make it a special day
for her, so that whenever she looked around, there was something to eat, something    
to drink, or something to read, or something interesting for her to do.
1. In _____, Mothering Sunday is in March.
A. Germany
B. England
C. America
D. China
2. Ann remembered that her mother _____ in the morning on Mothering Sunday.
A. had a cup of tea
B. got up late
C. collected a daffodil
D. had something to eat
3. What did Bill remember doing on Father's Day?
A. Doing housework.
B. Eating outside.
C. Going to the church.
D. Watching baseball games.
4. What's the text mainly about? 
A. The history of some national holidays.
B. The stories of some interesting holidays.
C. How to celebrate Mother's Day and Father's Day.
D. How to understand Mother's Day and Father's Day.
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选择题

What color ________ the socks? 　　[ ]

A. can

B. do

C. are

D. is

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