题干

一只小蜜蜂发现了一处蜜源,它立刻回巢招来10个同伴,可还是采不完.于是,每只蜜蜂回去分头各找来10只蜜蜂,大家再接着干,还是剩下很多蜜没有采.于是,蜜蜂们又回去叫同伴,每只蜜蜂又叫来10个同伴,但仍然采不完.蜜蜂们再回去,每只蜜蜂又叫来10个同伴.这一次,终于把这一片蜜源采完了.你来算一算采这块蜜源的蜜蜂一共有____ 只.

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    For many in the United States, Arab-Americans are an invisible part of the population. Though Arab-Americans as a community have made great contributions to American society in fields from literature to politics to medicine, many Americans know very little about Americans of Arab backgrounds.
    Arab history in the United States goes back to the late 1800’s when large numbers of Arab immigrants first began making their journey to a land known simply as “Amreeka”.
    Historians generally describe Arab immigration to America in two waves. The first wave took place between 1860 and 1924.The first wave consisted of Lebanese and Syrian, and some Egyptian immigrants. These new immigrants, who were mostly Christian, came to America in search of better opportunities. Even the doomed Titanic, which set sail for America in 1912,had close to a hundred Arab passengers aboard. The majority of Arab-Americans today are descendents of the first wave of immigrants; they are the third or more generation Americans.
The second wave of immigrants followed after World War Ⅱ,caused by political unrest in the Middle East. This second wave of immigrants consists of mainly Arab Muslims(穆斯林)and continues to this day.
    Arab-Americans make up 3 million of the population in the United States, according to demographers. And quite different from popular belief, 64 percent of them are American-born. Eighty-two percent of Arab-Americans are US citizens.
Arab-Americans are beyond the national average in both education and income. Education is important among Arab-Americans; 82 percent have high school diplomas, 36 percent have bachelor's degrees or higher, and 15 percent have graduate degrees. The-median(中位数的)average income among Arab-Americans is $39,580, which is higher than the US average.