2. 外语
  3. For centuries, humans have harnessed the power of biological systems to improve their lives and the world. Some argue that biote

For centuries, humans have harnessed the power of biological systems to improve their lives and the world. Some argue that biote

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问题    For centuries, humans have harnessed the power of biological systems to improve their lives and the world. Some argue that biotechnology began thousands of years ago, when crops were first bred for specific traits and microorganisms were used to brew beer. Others define the beginning of biotechnology as the emergence of techniques allowing researchers to precisely manipulate and transfer genes from one organism to another.【R1】______Genes are made up of DNA and are expressed into proteins, which do chemical work and form structures to give us specific traits. In the 1970s, scientists discovered and used the power of natural "scissors"— proteins called restriction enzymes — to specifically remove a gene from one kind of organism and put it into related or unrelated organisms. Thus, recombinant DNA technology, or what most experts now label as modern biotechnology, was born.
   The pioneers of biotechnology could not have envisioned our current abilities to engineer plants to resist disease, animals to produce drugs in their milk, and small particles to target and destroy cancer cells.【R2】______Genomics is based on these tools and is the study of genes and their functions. We have determined the composition of, or "sequenced," the entire set of genes for humans and several other organisms using biotechnology. 【R3】______
   Biotechnology, or really any technology, does not exist in a vacuum. It is derived from human efforts and affected by social, cultural, and political climates. Society drives and regulates technology, attempting to minimize the downsides and maximize the benefits.【R4】______Recent controversies over the use of genetically engineered organisms in food and agriculture have illustrated that this boundary is not so clear. Not only are there safety concerns about genetically engineered organisms, but there are also cultural differences in acceptance of the products.
   International contexts for technologies are important and should be considered.【R5】______On the other hand, there are social systems that are affected by new technologies and fears of creating greater divides between rich and poor if technology is not accessible to all sectors of society.
   A. The discovery of the structure of deoxyribonucleic acid (DNA) in the 1950s marks the start of this era.
   B. Many natural and physical scientists would prefer that the separation between social and ethical concerns and science and technology be well defined.
   C. Genomic information is helping us better to evaluate the commonalities and diversity among organisms and human beings and to understand and cure disease, even tailoring treatments to individuals.
   D. There are clear indications that biotechnology can benefit the poor and hungry of the world without harming the environment.
   E. Biotechnology is not a panacea for global problems, but it is a tool that holds a great deal of promise if used appropriately.
   F. However, biotechnology is more than engineering — it is also a set of tools for understandingbiological systems.
【R1】
选项
答案A
解析 本题的突破口是把握文章第一段的结构：以生物技术的起源为引子，以时间为线索概要地介绍人类发现和研究基因的过程。空格后的时间节点1970s也是提醒我们这里的逻辑顺序有可能为时间顺序。
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