[听力文本资源]Scientists are debating on how to limit their newly-discovered power to change genetic structure. Scientists already modify the genes of farm animals and agricultural plants to make them more productive or stronger. But now they can also change genes in wild animals and plants. These genes would continue into later generations.For example, it may be possible for scientists to remove from existence the kind of mosquitoes that carry the Zika virus. They might also be able to permanently remove species of plants and animals that are destructive to other species. In a published report, the U.S. National Academies of Sciences, Engineering, and Medicine (NASEM) said it supports continued research on this kind of gene control. But it warned that it is not possible to know what will happen when these changed plants and animals are released into the wild.Many people would support stopping mosquitoes and rats from carrying diseases. But scientists say we must understand the possible scientific, ethical, legal and social results of such action before we decide whether to take it. Gene modification is spread through reproduction. 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 are wondering what would happen if a modified organism mates with another species. 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.[听力文本资源]1. [听力文本资源] What do we know from the report published by the NASEM? [听力文本资源]A) NAS supports continued research on the gene control. B) NAS has proved that gene modification is basically safe.C) Genes of most species can be permanently modified.D) Scientists can remove the Zika virus from mosquitoes.2. [听力文本资源] How can changed genes spread according to the passage? [听力文本资源]A) By the reproduction of plants and animals. B) By mating with other modified genes.C) By being copied into newborns by scientists.D) By the development of new gene structures.3. [听力文本资源] What is scientists’ concern if modified species are released into the wild? [听力文本资源]A) Whether it is legal to take this action or not.B) It is hard to keep modified species within a country’s borders.C) Some creatures might be harmed or even become extinct. D) Modified organism will be less likely to mate with other species.

[听力文本资源]Scientists are debating on how to limit their newly-discovered power to change genetic structure. Scientists already modify the genes of farm animals and agricultural plants to make them more productive or stronger. But now they can also change genes in wild animals and plants. These genes would continue into later generations. For example, it may be possible for scientists to remove from existence the kind of mosquitoes that carry the Zika virus. They might also be able to permanently remove species of plants and animals that are destructive to other species. In a published report, the U.S. National Academies of Sciences, Engineering, and Medicine (NASEM) said it supports continued research on this kind of gene control. But it warned that it is not possible to know what will happen when these changed plants and animals are released into the wild. Many people would support stopping mosquitoes and rats from carrying diseases. But scientists say we must understand the possible scientific, ethical, legal and social results of such action before we decide whether to take it. Gene modification is spread through reproduction. 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 are wondering what would happen if a modified organism mates with another species. 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.[听力文本资源]1. [听力文本资源] What do we know from the report published by the NASEM? [听力文本资源]A)  NAS supports continued research on the gene control. B)  NAS has proved that gene modification is basically safe.C)  Genes of most species can be permanently modified.D)  Scientists can remove the Zika virus from mosquitoes.2. [听力文本资源] How can changed genes spread according to the passage? [听力文本资源]A)  By the reproduction of plants and animals. B)  By mating with other modified genes.C)  By being copied into newborns by scientists.D)  By the development of new gene structures.3. [听力文本资源] What is scientists’ concern if modified species are released into the wild? [听力文本资源]A)  Whether it is legal to take this action or not.B)  It is hard to keep modified species within a country’s borders.C)  Some creatures might be harmed or even become extinct. D)  Modified organism will be less likely to mate with other species.