As many countries emerge from lockdowns, researchers are prepared to use genome sequencing to avoid an expected second wave of C

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问题     As many countries emerge from lockdowns, researchers are prepared to use genome sequencing to avoid an expected second wave of COVID-19 infections. Since the first whole-genome sequence of the new coronavirus, SARS-CoV-2, was shared online on 11 January, scientists have sequenced and shared some 32,000 viral genomes from around the world. Such a vast amount of data has allowed researchers to trace the origin of COVID-19 outbreaks in their countries and pinpoint when community transmission occurred.
    Now, countries that have successfully suppressed infections are entering the next phase of the COVID-19 pandemic—where there’s a risk of new cases appearing as social restrictions ease. Researchers say that genomics will be crucial to quickly track and control these outbreaks. Studies already show that outbreaks tend to be shorter and smaller when genomics is used to help contact tracing. "When there are few cases, genomics can very quickly tell you what you’re dealing with and therefore guide precision interventions," says Gytis Dudas, a consulting bioinformatician at the Gothenburg Global Biodiversity Centre in Sweden.
    Several places are particularly well placed to do that because they invested in genome sequencing early in the pandemic and have a relatively small number of cases. Researchers in New Zealand, and at least one state in Australia decided that they would aim to sequence most coronavirus genomes in their country or state. As SARS-CoV-2 spread around the world, distinct lineages began to form as viruses circulating in different regions gradually evolved. By comparing sequences, researchers can quickly rule out possible lines of transmission if two sequences don’t match, or link together cases that do.
    Scientists in the United Kingdom, the United States and other countries are also sequencing SARS-CoV-2 from a large proportion of cases there, but because their epidemics are still ongoing and case numbers are high, genomics is being used to monitor spread and help identify the source of some cases where contact tracing fails. But such interventions depend on broad sampling, and so in places where diagnostic testing is limited, there will also be gaps in the genomic data.
    But the use of genomic analysis to help contact tracing is largely restricted to high-income countries, says Meru Sheel, an epidemiologist at the Australian National University in Canberra. She would like to see genomics considered as a tool for outbreak responses in resource-limited countries in the Asia-Pacific region, as it was in the Democratic Republic of the Congo, Sierra Leone and Guinea during the Ebola outbreak.
According to Paragraph 1, which of the following statements about the genome sequence can be inferred?

选项 A、It was only shared to scientists.
B、With it, the origin of COVID-19 can be traced.
C、It cannot be applied to prevent the second wave of COVID-19 pandemic.
D、It was shared through a virtual method.

答案D

解析 推断题。根据题干可定位至第一段。A项和D项对应第一段第二句“since the first whole-genome sequence of the new coronavirus,SARS-CoV-2,was shared online on 11 January”,即“自从新的冠状病毒SARS-CoV-2的首个全基因组序列于1月11日在网上共享以来”,由此可知全基因组序列不是只被分享给了科学家,因此A项错误;全基因组序列是在网上共享的,D项中virtual method是对原文中shared online的同义替换,故为正确答案。第一段并没有提及如何追溯此次疫情的源头。只提到了trace the origin of COVID-19 outbreaks in their countries,即“追踪各国新冠肺炎疫情的起源”,B项属于张冠李戴,故排除。第一段第一句提到researchers are prepared to use genome sequencing to avoid an expected second wave of COVID-19 infections,即“研究人员准备利用基因组测序来避免预计到来的第二波新冠肺炎疫情感染”,C项与原文表述相反,也排除。
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