Do you have any foreign friends? Do you know their characteristics（特征）?

    The Germans are very quiet and they always keep calm. They don't like to speak more words. They look very serious. They like different kinds of amusements（娱乐）. The Germans are very hard－working. They like tidiness, especially the women, who always keep their home clean.

    In some ways, the Englishmen look the same as the Germans. They are very quiet and never talk too much with the strangers. They are really polite, so we often hear they say “Thank you.” Or “Sorry.” The gentlemen are also the Englishmen.

    The French's holidays are very long. They like traveling and usually spend their long time staying in other countries. The Frenchmen are more outgoing than the Germans. It is very easy to make friends with them.

    Compared to the Frenchmen, the Americans are more outgoing. And they are even opener than all of the Europeans（欧洲人）. They don't like to depend on others. So it is very common that the students do part-time jobs in their free time. And in Americans' eyes, success is an important part in their life.

在下列转化关系中，各物质均是初中化学常见物质，其中甲、乙、丙属于单质，A为黑色固体，C属于盐．①甲+乙 B ②甲+丙 A

③A+D→C+B ④C+E→Cu（OH）₂↓+NaCl

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