题干

关于原子结构及原子核的知识,下列判断正确的是(   )

A:处于n=3的一个氢原子回到基态时一定会辐射三种频率的光子

B:α射线的穿透能力比γ射线强

C:氢原子核外电子从半径较小的轨道跃迁到半径较大的轨道时,原子的总能量增大,电子的动能也增大

D:放射性元素的半衰期与压力、温度无关

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D

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(C)

    Walter Dean Myers,born on August 12,1937,was an American writer of children's books.He was known for young adult literature (文学) He wrote more than 100 books,including picture books and non﹣fiction."I care about writing for young people because I remember how much I needed help and guidance at that time in my life,"Myers said in his book.

    Myers loved writing.He got up at five o'clock every morning.He worked at home in a small office that used to be his son's bedroom.

    Myers would first write an outline for every book.He called this prewriting.He imagined what the story would be and wrote down ideas in a notebook.To make sure there's enough action and dialogue for a good story,he thought of 30scenes.He wrote a short description of each scene in his notebook.

    He also cut out pictures of real people and put them on his office walls.He looked at those pictures and came up with ideas.Once he knew what the story would be and who the characters were,he began to write the book.He wrote five pages a day on his computer.

    Myers usually worked on three books at a time.When he was not prewriting or writing a book,he might be rewriting something he had already completed.Then he would send the story to his agent (经纪人).He or she made suggestions for the story.After these final changes were made,the book was published and made its way to bookstores and libraries.By that time,Myers would begin to write his next book."I want to do the best that I can with my writing."said Myers.