模块综合练05 模块五-2022年高考英语一轮复习小题多维练（北师大版）

北师大版 模块综合练05 模块五 时间：100分钟 总分：120分 考试范围：模块一Unit13-15 第二部分 阅读理解（共两节，满分40分） 第一节（共15小题；每小题2分,满分30分） 阅读下列短文，从每题所给的四个选项（A、B、C和D）中，选出最佳选项，并在答题卡上将该项涂黑。 A （2021·陕西·高三月考）Based on bone and tooth records, mammoths（猛犸象）were thought to have gone extinct about 12,000 years ago. But a new genetic sampling technique suggests the great beasts may have stuck around a lot longer. The story is in the soil. Bones are rich sources of prehistoric genetic information, but not the only ones; items ranging from shed Ice Age skin cells to pine needles can contribute to the genetic record stored in dirt. Paleogeneticists（古遗传学家）have been analyzing "environmental DNA" from soil for a long time, but getting rid of non-DNA material without destroying these fragile clues is daunting（使人气馁的）. "Environmental samples contain a huge range of other chemical substances that are hard to separate from the DNA," says McMaster University geneticist Tyler Murchie. "We can't afford to lose whatever we can get." In the new approach, soil samples are got and then broken into smaller portions, stirred and run through a "cold spin method" to separate as much DNA as possible. The DNA is then compared against an existing genetic library to detect species matches. The method is limited because researchers using it need to know what DNA to look for. If a saber-toothed cat species is not already in the genetic library, the analysis cannot detect that animal. For known species, however, the process may yield exciting information. In their study, the researchers detected about 2,100 kinds of plants and 180 animals. Not yet published results from other field sites are yielding similar results, Murchie says, and future fossil discoveries could strengthen the case. "We can use this approach to identify species in places and times we never knew they existed," he adds. 1．Why does the author mention "mammoths" in Paragraph 1? A．To present a fact. B．To show us an extinct animal. C．To correct a mistake. D．To introduce the