话题17：生物多样性及保护 2023届高考英语阅读理解最新热点话题预测分类训练（全国通用）

【高考英语三轮冲刺】话题17 生物多样性及保护10篇 2023届高考英语阅读理解最新热点话题分类训练（全国通用） 1.（2023·湖南邵阳·统考二模） Our Planet Earth is full of life and has incredible biodiversity. Biological Diversity or Biodiversity is the base of human existence and fundamental to its well-being. Species are the building blocks of this life on Earth, and it is believed that the species that are at present globally found have continuously evolved over 65 million years since the Last Mass Extinction. However, the nature and extent of our planet’s biodiversity at all levels have not been completely evaluated yet. Thus, the exact number of species found in the world remains unknown. Over the years, with the advancement of scientific knowledge and the discovery of more new species, it has been approximated that there are, at present, 10 million to 14 million species on Earth, of which 1.2 million species have been data-based. This means that still more than 86％ of the terrestrial(陆生的) and 91％ of the marine species remain unknown. Every year, taxonomists(分类学家)describe thousands of species,some of which are completely new to science, while in some cases, the species and subspecies are closely examined and determined whether they can be considered distinct species. A study has revealed that over 99. 9% of all species amounting to more than 5 billion species that ever lived here, are believed to be extinct. At present, our planet houses millions of species, among which 86% live on land, 13% in the deep subsurface, and a mere 1% in the oceans. However, Biodiversity is not evenly distributed on Earth, and its number varies greatly on different continents. The undiscovered and misidentified species slow our ability to understand patterns and changes in global biodiversity and the rate of species extinctions(灭绝). Even after several years of taxonomic studies, only 14% of terrestrial species and 9% of marine species have been officially added to the central database. Necessarily, some species will become extinct before resear