题目

阅读下面材料，在空白处填入适当的内容(1个单词)或括号内单词的正确形式。 The U.S. Library of Congress contains 167 million items, has 838 miles of bookshelves and adds 12,000 articles of history daily. It is one of the largest libraries in the world, which (set) up on the same day in 1800 as President John Adams signed a bill, (order) the seat of government to be transferred from Philadelphia to the new capital city of Washington. As its name suggests, the library was (origin) for members of Congress only, but its role as the leading research arm of the governme水华是富营养化水体常见的一种自然现象，从种群特征分析，水华属于 A．不规律波动            B．不均匀分布            C．短期内暴长            D．季节性消长