依据所学化学知识回答: (1)奥运火炬燃烧时主要是将化学能转变成 能和 能;

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问题:

依据所学化学知识回答:

(1)奥运火炬燃烧时主要是将化学能转变成             能和            能;火炬铝柄表面有一层致密的氧化铝保护膜,它是常温下铝与氧气反应生成的,该反应的化学方程式为:                     

(2)将“嫦娥一号” 送上太空的火箭推力巨大,因为它所使用的燃料是液氢、助燃剂是液氧,则液氢燃烧的化学方程式为                ;液氢作燃料除了单位质量燃烧的热能最大以外,还有一个与环保有关的优点是             

(3)能用来证明铜比银活泼的化学反应方程式为                  ,该反应的基本反应类型是              反应。

考点:燃料的利用和新能源的开发置换反应化学反应方程式的书写燃烧与燃烧的条件
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《海国图志》系统阐述了“师夷长技以制夷”的思想。该书的作者是[ ]

A.洪仁玕

B.梁启超

C.魏源

D.姚莹

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软件测试的目的是

A.证明软件系统中存在错误

B.找出软件系统中存在的所有错误

C.尽可能多地发现系统中的错误和缺陷

D.证明软件的正确性

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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.

Which of the following conclusions about Phyllis is supported by the passage

A.She would have been more recognized as a poet if she had not been black.

B.She would have written poetry if she had stayed in Africa.

C.She went unrecognized as a poet during her lifetime.

D.She only wrote religious poetry.

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现浇钢筋混凝土楼梯的结构形式有哪几种?

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药包置入井口后,缓缓向井中推进药包,推进()时,连接第二根爆炸杆。

A、1米

B、5米

C、2米

D、5米

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