2. 外语
  3. When Louise Brown was born on 25 July 1978, she kicked off an era. The first "test tube baby" is a mother herself now, and she’s

When Louise Brown was born on 25 July 1978, she kicked off an era. The first "test tube baby" is a mother herself now, and she’s

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问题     When Louise Brown was born on 25 July 1978, she kicked off an era. The first "test tube baby" is a mother herself now, and she’s been joined by millions of others born with the【C1】______of in vitro fertilization(体外受精), or IVF. Now specialists wonder whether people who were conceived by IVF are likely to be【C2】______.
    "By and large, the kids are just fine. It’s not like the kids having【C3】______arms or heads," says Carmen Sapienza, a scientist at Temple University. But none is older than their early 30s, and the vast【C4】______are under the age of 20, so they haven’t had time for long-term health problems to show up.
    One source of worry is that so many IVF babies have low birth weight. Children-conceived through IVF are more likely to【C5】______less than 2.5 kilograms than are babies conceived【C6】______. That could spell trouble ahead, because low-birth-weight babies often have long-term health problems. They’re more likely to be obese, to have diabetes(糖尿病)or other problems.
    With that in mind, Sapienza and colleagues have looked at genes that are likely to play a role in such health problems. They found that certain DNA-patterns, which affect how genes are【C7】______, are different between IVF and non-IVF children. There’s no way to tell if that’s because of the【C8】______used to produce the IVF babies or whether the difference has something to do with the underlying infertility problem the parents had. It’s also【C9】______whether these gene-expression differences will translate into health differences. But it does suggest that children conceived by IVF are【C10】______on some level.
A)weigh E)unclear I)unique M)majority
B)technology F)naturally J)healthy N)minority
C)help G)expressed K)explained O)completely
D)unsure H)procedure L)extra
【C10】
选项
答案I
解析 此处应为形容词。上文提到各种不确定因素，此空所在句句首用But表转折，说明由体外受精生出的小孩在某种程度上是“独一无二的”，选unique。
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大学英语四级

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