我国水旱灾害比较频繁的最主要原因是（   ）

列宁说：“当正面攀登受到阻碍、不能前进到山顶时，就要有勇气走一段困难、危险的下山路，去寻找能够登上山顶的新路线。”文中“走一段困难、危险的下山路”在苏联的社会主义建设中具体是指(　　)。

    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.