Scientists are debating how to limit their newly-discovered power to change geneticstructure. Scientists already modify the genes of farm animals and agricultural plants to makethem more productive or stronger. But now they can also change genes in wild animals andplants. These genes would continue into later generations. For example, it may be possiblefor scientists to remove from existence the kind of mosquitoes that carry the Zika virus. Theymight also be able to permanently remove species of plants and animals that are destructive toother species.
In a report published last week, the U. S. National Academies of Science s, Engineeringand Medicine (NAS) said it supports continued research on this kind of gene control. But itwarned that it is not possible to know what will happen when these changed plants andanimals are released into the wild.
Sixteen biologists, ethicists(伦理学家) and policymakers are on an NAS committee thatis examining the issue. They say that there is value to the new technology. But, they say,there is not enough evidence to support the release of modified organisms (生物体) from thelaboratory into nature.
Many people would support stopping mosquitoes and rats from carrying diseases. Butscientists say we must understand the possible scientific, ethical, legal and social results ofsuch action before we decide whether to take it. Gene modification is spread throughreproduction(繁殖).
Changed genes will continue to spread as long as an animal or plant continues to
reproduce. They cannot be limited to a farm or kept within a country's borders. Scientists arewondering what may happen if a modified organism mates with another species. They are notyet sure how the modified genes would affect the other species. It is possible that those genescould harm those creatures or even lead to their disappearance from our planet.
32. What possible advantage does gene control in wild animals and plants have?
A. Changing the Zika virus permanently.
B. Removing the destructive species for ever.
C. Having changed genes in their next generations.
D. Making all the species more productive and stronger.
33. As for genetically changed wild animals and plants ,what are scientists worried about?
A. They may become weaker or die out.
B. They may be more productive.
C. They may cause damage to their living habitat.
D. Their genes may spread to later generations.
34. Which of the following is NOT true according to the passage?
A. Scientists are not sure what exact results gene modification leads to.
B. Scientists won't modify any genes before they make the final decision.
C. Gene modification has benefited some farm animals and agricultural plants.
D. Scientists have not applied gene modification to wild animals and plants in case ofpossible danger.
35. What can be the best title for the passage?
A. Stop research on gene control
B. How to change genetic structure
C. Power and danger of gene control
D. Advantages of gene control in wild animals and plants
参考答案：32.B 事实判断题。根据第一段：They might also be able to permanently remove species of plants and animals that are destructive to other species可得答案。
33.A 推理判断题。根据最后一段：It is possible that those genes could harm those creatures or even lead to their disappearance from our planet可知答案。
34.B 细节理解题。根据第一段：Scientists already modify the genes of farm animals and agricultural plants to make them more productive or stronger可得答案。
35.C 标题猜测题。根据第一段：Scientists already modify the g enes of farm animals and agricultural plants to make them more productive or stronger和They might also be able to permanently remove species of plants and animals that are destructive to other species和最后一段：They are not yet sure how the modified genes would affect the other species. It is possible that those genes could harm those creatures or even lead to their disappearance from our planet可得答案。