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  3. Dorothy Crowfoot Hodgkin When Dorothy Crowfoot Hodgkin was ten years old, she watched her first crystals form on a string dangli

Dorothy Crowfoot Hodgkin When Dorothy Crowfoot Hodgkin was ten years old, she watched her first crystals form on a string dangli

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问题                         Dorothy Crowfoot Hodgkin
When Dorothy Crowfoot Hodgkin was ten years old, she watched her first crystals form on a string dangling in a glass of salt water. Many children before and since have done the same, but in Hodgkin’s case, the sparkling geometric shapes kindled a fascination that would lead her to world fame.
    In 1964, nearly half a century later, Hodgkin received a Nobel Prize in Chemistry for discovering the structures of penicillin and vitamin B12 from photographic images of their crystals. She made the images with a technique called x-ray crystallography, which involves firing x-rays through a crystal to determine the arrangement of the atoms in it. It is a bit like determining the shape of a jungle gym from its shadow.
    Born in 1910, Hodgkin spent the first few years of her life in Cairo, where her father was an official in the British colonial government. Most of her education had been at home, but once back at school in England, her keen interest in crystals won the attention of her schoolteacher. Hodgkin and a friend got special permission to join the boys studying chemistry. By age 12, she was doing chemistry experiments on rocks she found in her garden to see what they contained.
    That summer, while visiting her father in Khartoum, Sudan, she met Dr. A. E. Joseph, a friend of her father’s and a well-known soil chemist. Joseph took her on a tour of his laboratory. Pleased by her intense interest, he put together a small chemistry set for her, which she took back to England and set up in her mother’s attic. It was her first laboratory.
    Hodgkin enrolled at Oxford University, where she eventually specialized in x-ray crystallography. At the time, the analysis of the structures of even the simplest chemicals by x-ray crystallography required at least 30 sets of calculations, all done by hand. The work demanded perseverance and diligence, and a good head for math. Under these conditions, Hodgkin flourished.
    Seeking a greater challenge after college, Hodgkin went to Cambridge to study with a young crystallographer named J. D. Bernal. Together they solved some of the most complex chemical structures ever attempted, including those of several vitamins and sex hormones. They took the first x-ray photographs of a protein- the stomach enzyme pepsin- showing that proteins form regular crystals.
    In 1937, Hodgkin received her doctorate. Within a few months, she also married historian Thomas Hodgkin, taking his name. The Hodgkins were a two-career family, working in different towns and commuting on alternate weekends to see each other. Dorothy Hodgkin remained at Oxford, where she continued her research, taught university classes, and raised three children.
    When the demand for penicillin soared during World War II , chemists all over the world raced to determine its structure. Experimental chemists used chemical reactions. Structural chemists, such as Hodgkin, used crystallography. Despite daunting calculations, Hodgkin and her students at Oxford completed the structure in 1949, beating the experimental chemists and establishing x-ray crystallography as an indispensable tool in biochemistry. Even as Hodgkin was finishing her analysis of penicillin, however, she had already begun a study of B12, widely used to treat pernicious anemia. In 1957, she published the structure of this 180-atom molecule.
     (A) When she was awarded the Nobel Prize in 1964, she told a group of students at the ceremonies in Stockholm, Sweden, that she hoped her position as the only woman to receive the prize that year "will not be so very uncommon in the future, as more and more women carry out research in the same way as men".
     (B)But what was perhaps Hodgkin’s greatest success came after the Nobel Prize, when she tackled the biggest molecule of her career. Insulin, a protein that regulates the body’s sugar storage, contains over 1 000 atoms.(C) A deficiency in or insensitivity to insulin causes diabetes, a complex disease that causes suffering in several hundred million people worldwide. Hodgkin solved the structure of insulin in only five years.(D) Her achievement proved that proteins have regular shapes, and it spawned research that ultimately led to effective treatments for diabetes.
The word it in Paragraph 2 refers to
选项 A、Testing out the structures of penicillin
B、Testing out the structures of vitamin B12
C、Determining the arrangement of the atoms in a crystal
D、Firing x-rays through a crystal
答案C
解析 本题为指代关系题，考查考生能否认定代词与篇章中其他词语的指代关系。题目问：第二段中的it指代的是什么?it所在句子“It is a bit like determining the shape of a jungle gymfrom its shadow”的意思是“它有点儿像根据儿童攀援游戏立体构架的影子来决定其形状”。根据此句，it应该也是决定(determining)某个事物，因为比较的双方通常应该是对等的。因此选C。A项(测试出盘尼西林的结构)、B项(测试出维生素B12的结构)和D项(用X光穿透水晶)都不是it所指代的对象。
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