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问题 单项选择题

设文件索引节点中有8个地址项，每个地址项大小为4字节，其中5个地址项为直接地址索引，2个地址项是一级间接地址索引，1个地址项是二级间接地址索引，磁盘索引块和磁盘数据块大小均为1KB字节。若要访问文件的逻辑块号分别为5和518，则系统应分别采用______。

A．直接地址索引和一级间接地址索引
B．直接地址索引和二级间接地址索引
C．一级间接地址索引和二级间接地址索引
D．一级间接地址索引和一级间接地址索引

答案

参考答案：C

解析： 依题意，5个直接地址索引可以表示5×1KB=5KB，其逻辑块号是0-4；一级间接地址索引可以产生的索引项为1024/4=256，一级间接索引可以表示256×1KB=256KB，2个一级间接地是索引表示256×2=512KB，其逻辑块号是5～511；二级间接索引产生的二级间接索引项也为256，因此二级索引表示256×256KB=65536KB，其逻辑块号是512-65535。
由于5＞4，因此要访问逻辑块号为5的文件，系统应采用一级间接地址索引。而518＞511，要访问逻辑块号为518的文件，则系统应采用二级间接地址索引。

名词解释

民粹派作家
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单项选择题


Phyllis Wheatley is regarded as America’s first black poet. She was born in Senegal, Africa, about 1753 and brought to America aboard a slave ship at about the age of seven. John and Susannah Wheatley bought her for three pounds at a slave auction in Boston in 1761 to be a personal servant of Mrs. Wheatley. The family had three other slaves, and all were treated with respect. Phyllis was soon accepted as one of the family, which included being raised and educated with the Wheatley’s twin 15-year-old children, Mary and Nathaniel. At that time, most females, even from better families, could not read and write, but Mary was probably one of the best educated young women in Boston. Mary wanted to become a teacher, and in fact, it was Mary who decided to take charge of Phyllis’s education. Phyllis soon displayed her remarkable talents. At the age of twelve she was reading the Greek and Latin classics and passages from the Bible. And eventually, Mrs. Wheatley decided Phyllis should become a Christian.
At the age of thirteen Phyllis wrote her first poem. She became a Boston sensation after she wrote a poem on the death of the evangelical preacher George Whitfield in 1770. It became common practice in Boston to have "Mrs. Wheatley’s Phyllis" read poetry in polite society. Mary married in 1771, and Phyllis later moved to the country because of poor health, as a teacher and caretaker to a farmer’s three children. Mary had tried to interest publishers in Phyllis’s poems but once they heard she was a Negro they weren’t interested.
Then in 1773 Phyllis went with Nathaniel, who was now a businessman, to London. It was thought that a sea voyage might improve her health. Thirty-nine of her poems were published in London as Poems on Various Subjects, Religious and Moral. It was the first book published by a black American. In 1775 Phyllis wrote a poem extolling the accomplishments of George Washington and sent it to him. He responded by praising her talents and inviting her to visit his headquarters. After both of her benefactors died in 1777, and Mary died in 1778, Phyllis was freed as a slave. She married in 1778, moved away from Boston, and had three children. But after the unhappy marriage, she moved back to Boston, and died in poverty at the age of thirty.

The underlined word "respect" in Paragraph 1 is closest in meaning to

A．consideration

B．disregard

C．punishment

D．behavior
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