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

【C9】