Cloning and DNA
Many people think that the science of genetics① and cloning is recent. It's certainly true that② in 1953, Watson and Crick, two scientists at Cambridge University, England, discovered the structure of the acid③ DNA — a transparent④ twisting⑤ ladder made of the fundamental⑥ components⑦ of life⑧. But in fact, it was in 1866 that⑨ Mendel first recorded the results of growing pea plants. He understood that both the parent plants had influenced the genetic makeup⑩ of the new plant.
In 1973, biochemists Cohen and Boyer discovered a procedure? to use enzymes? — chemicals? formed in the body — to unzip? the DNA, to cut out? a sequence of? genes?， and finally to insert? them into the host cell? and combine with? its DNA.
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①genetics/d??'netIks/ n．遗传学
②that引导主语从句，it作形式主语。
③acid/'æsId/ adj.酸(性)的
④transparent/træns'pær?nt/ adj.透明的
⑤twisting/'twIstI?/ adj.扭曲的，弯曲的
⑥fundamental/?f?nd?'mentl/ adj.基本的，不可或缺的
⑦component/k?m'p??n?nt/ n．成分
⑧made of ...是过去分词短语作后置定语。
⑨it was ... that ...是强调句型，强调时间状语in 1866。
⑩makeup n．构成，构造
?procedure/pr?'si?d??/ n．程序，注意其后接了四个to do。
?enzyme/'enzaIm/ n．酶 ?chemical n．化学物质
?unzip/?n'zIp/ v．解开 ?cut out 切割出来，分离
?a sequence of一系列的 ?gene/d?i?n/ n．基因
?insert/In's??t/ v．植入，插入 ?the host cell宿主细胞
?combine with 与……结合
be combined with 被与……结合/联合在一起
