问题
选择题
2007年9月，美国科学家宣称：普通盐水在无线电波的照射下可燃烧，这项伟大的发现，有望解决用水作人类能源的重大问题。无线电频率可以降低盐水中所含元素之间的“结合力”，释放出氢原子，若点火，氢原子就会在该种频率下持续燃烧。上述中“结合力”实质是[ ]
A．分子间作用力
B．氢键
C．非极性共价键
D．极性共价键
答案
答案：D
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2007年9月，美国科学家宣称：普通盐水在无线电波的照射下可燃烧，这项伟大的发现，有望解决用水作人类能源的重大问题。无线电频率可以降低盐水中所含元素之间的“结合力”，释放出氢原子，若点火，氢原子就会在该种频率下持续燃烧。上述中“结合力”实质是[ ]
A．分子间作用力
B．氢键
C．非极性共价键
D．极性共价键
答案：D
| Children’s literature traces its beginnings to preliterate times, when ancient storytellers passed tales and legends from generation to generation in the oral tradition. William Caxton, who established England’s first printing press, published books of etiquette, fables and legends. However, these didn’t constitute a body of work that could be considered literature for children. Because children at that time were considered "miniature adults", books were didactic in nature. The content for young readers consisted mainly of religious instruction, rules of behavior, ethical messages, and moral platitudes. In 1774, Englishman John Newberry changed children’s publishing when he began to create books with attractive formats, quality illustrations, and sturdy bindings, that were designed primarily for children to enjoy. The oldest, and most prestigious award given for children’s books published in America, is the Newberry Medal. In the following century, children’s literature began to bloom. Hans Christian Andersen’s wonderful stories like "The Ugly Duckling", and "The Little Mermaid", and Grimm brothers collected two volumes of German folktales that included stories such as "Snow White" and "Rumpelstiltskin". Childhood came to be recognized as a joyful and carefree period of life, and books celebrating it began to be published. Charles Dodgson (Lewis Carrol) wrote the fantasy "Alice in Wonderland", the first book that was intended purely for children’s enjoyment without any pretense of instruction. Edwards Lear’s books of nonsense poetry delighted both young and old readers. In North America, books for a young audience were becoming popular as well. Kate Douglas Wiggin wrote "Rebecca of Sunnybrook Farm", Louisa May Alcott wrote "Little Women", and Samuel Clemens (Mark Twain) created Tom Sawyer and Huckleberry Finn. By the end of the century, the pious and moralistic books of earlier times had been replaced by writing designed to amuse and entertain a young audience. In the 1800s color printing was introduced, and by the middle of the 19th century, the rough illustrations that characterized earlier children’s books had been replaced by works of art that captured the word and some of the story. |
What impact did color printing have on children’s books
A．Sales increased by the middle of the 19th century.
B．Rough illustrations were now more appealing.
C．Illustrations told more of the story and were more appealing.
D．Books became more amusing.