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
【C4】
选项
答案M
解析 此处应为名词。上文说到“没人年龄超过30来岁”，据此可知此处应该表达“大部分在20岁以下”，the vast majority是常见表达，表示“绝大多数”，符合语义，故选majority。
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