It was 10 years ago, on a warm July night, that a newborn lamb took her firs

游客2023-08-22  22

问题     It was 10 years ago, on a warm July night, that a newborn lamb took her first breath in a small shed in Scotland. From the outside, she looked no different from thousands of other sheep born on【C1】______farms. But Dolly, as the world soon came to realize, was no【C2】______lamb. She was cloned from a single cell of an adult female sheep,【C3】______long-held scientific dogma that had declared such a thing biologically impossible.
    A decade later, scientists are starting to come to grips with just how different Dolly was. Dozens of animals have been cloned since that first lamb—mice, cats, cows and, most recently, a dog—and it’s becoming【C4】______clear that they are all, in one way or another, defective.
    It’s【C5】______to think of clones as perfect carbon copies of the original. It turns out, though, that there are various degrees of genetic【C6】______. That may come as a shock to people who have paid thousands of dollars to clone a pet cat only to discover that the baby cat looks and behaves【C7】______like their beloved pet—with a different-color coat of fur, perhaps, or a【C8】______different attitude toward its human hosts.
    And these art just the obvious differences. Not only are clones【C9】______from the original template(模板)by time, but they are also the product of an unnatural molecular mechanism that turns out not to be very good at making【C10】_______ copies. In fact, the process can embed small flaws in the genes of clones that scientists are only now discovering.
A)abstract I)nothing
B)completely J)ordinary
C)deserted K)overturning
D)duplication L)separated
E)everything M)surrounding
F)identical N)systematicaly
G)increasingly O)tempting
H)miniature [br] 【C3】

选项

答案 K

解析 空格位于long-held scientific dogma之前,且在逗号之后,故推测此处可能是一个独立成分,即现在分词短语作状语。根据后文,科学教条主义认为克隆从生物学角度讲是不可能实现的,而上文中却阐述了克隆羊的事实,故这一事实推翻了科学教条主义。因此overmrning符合句意,为正确答案。备选项中只有一个现在分词,其他动词均可排除。
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