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问题 选择题

Na2O2、Cl2、SO2等均能使品红溶液褪色。下列说法正确的是

A．Na2O2、Cl2、SO2依次属于电解质、单质、非电解质

B．标准状况下，1 mol Na2O2和22.4LSO2反应生成Na2SO4，转移电子数目为NA

C．等物质的量Cl2和SO2同时通入品红溶液，褪色更快

D．在Na2O2中阴阳离子所含的电子数目相等

答案

答案：A

题目分析：A选项分类正确，B选项中发生1mol的反应转移2mol的电子，所以转移电子数目为2NA。C选项中氯气和二氧化硫溶于水会发生反应生成硫酸和盐酸，漂白性质消失。D中Na2O2阳离子电子数=11×2-2=20，阴离子电子数=8×2+2=18,电子数目不相等。

点评：本题每个选项考查了不同的知识点，综合性较强，属于简单题。

单项选择题


The Frugal Gourmet Cooks American
by Jeff Smith
Our real American foods have come from our soil and have been used by many groups— those who already lived here and those who have come here to live. The Native Americans already had developed an interesting cuisine using the abundant foods that were so prevalent.
The influence that the English had upon our national eating habits is easy to see. They were a tough lot, those English, and they ate in a tough manner. They wiped theft mouths on the tablecloth, if there happened to be one, and they ate until you would expect them to burst. European travelers to this country in those days were most often shocked by American eating habits, which included too much fat and too much salt and too much liquor. Not much has changed! And, the Revolutionists refused to use the fork since it marked them as Europeans. The fork was not absolutely common on the American dinner table until about the time of the Civil War, the 1860s. Those English were a tough lot.
Other immigrant groups added their own touches to the preparation of our New World food products. The groups that came still have a special sense of self-identity through their ancestral heritage, but they see themselves as Americans. This special self-identity through your ancestors who came from other lands was supposed to disappear in this country. The term melting pot was first used in reference to America in the late 1700s, so this belief that we would all become the same has been with us for a long time. Thank goodness it has never worked. The various immigrant groups continue to add flavor to the pot, all right, but you can pick out the individual flavors easily.
The largest ancestry group in America is the English. There are more people in America who claim to have come from English blood than there are in England. But is their food English Thanks be to God, it is not! It is American. The second largest group is the Germans, then the Irish, the Afro-Americans, the French, the Italians, the Scottish, and the Polish. The Mexican and American Indian groups are all smaller than any of the above, though they were the original cooks in this country.

Which of the following statements is true

A．People from other cultures or nations start to lose their self-identity once they get settled down in America.

B．The "melting pot" is supposed to melt all the foods but in reality it doesn’t.

C．The special sense of self-identity of people from other countries can’t be main- mined once they become Americans.

D．The "melting pot" finds it capable of melting all the food traditions into the American tradition.
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多项选择题

食物中毒的发病特点是什么？（）

A.潜伏期短，来势急剧，呈爆发性；

B.发病与食物有关，未食用者不中毒，停止食用后发病停止；

C.中毒病人有相似的临床表现；

D.一般无人与人之间的直接传染；

E.有明显的季节性。
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