12.课时梯级训练(十二) Section Ⅳ Writing（Word练习）-【优化指导】2023-2024学年新教材高中英语选择性必修第四册（人教版2019）

课时梯级训练(十二)　Section Ⅳ　Writing Ⅰ.阅读理解 A (2023·济南高二检测)Scientists have found the world's biggest seagrass ecosystem in the Bahamas.Seagrass refers to dozens of different species of flowering plants that live entirely underwater，producing energy through photosynthesis(光合作用) by absorbing sunlight.Like their land­based relatives，seagrasses have roots and leaves and also produce seeds.Seagrasses grow in salty coastal waters around the world，usually in shallow waters where sunlight is more plentiful.Since seagrasses carry out the process of photosynthesis，they are known to be very effective at storing carbon dioxide，the greenhouse gas.This is because photosynthesis involves plants using sunlight to transform carbon dioxide into oxygen. These underwater plants play an important role in carbon sequestration，in which carbon is stored in the environment rather than being allowed to float freely in the atmosphere where it can contribute to global warming.According to Gallagher，one of the new study's authors，carbon enters the ocean as part of the carbon cycle，and the seagrass takes in this carbon through photosynthesis via their leaves.This is part one.The second part is when the seagrass transports this carbon through itself，burying and storing it in its root system.Seagrass stores this carbon permanently. The purpose of the study by Gallagher and his colleagues was to map seagrass in the Bahamas，using data from 15 tiger sharks equipped with tracking instruments that could also take images of the sea floor.That information was then combined with reports from 2，500 surveys by human divers. Mark Huxham，professor of teaching and research in environmental biology，said, “This brilliant study uses imaginative and exciting new technology，in partnership with tiger sharks.We know seagrass is important for the health of our seas and our planet，but there are major gaps in our understanding about it.” 1．What is Paragraph 1 mainly about? A．The cause of photosynthesis. B．The living condition