Unit 5 A delicate World Starting out+Using language 课件-2025-2026学年高二外研版英语选择性必修第二册

该高中英语课件围绕“Unit 5 A delicate world”展开，核心知识点包括“delicate”的多维度释义（脆弱性、精细结构、自然美）及生态系统的构成与人类影响。课堂通过视频导入，结合拼图和木棍游戏比喻引导学生理解生物多样性重要性，从词汇释义到生态系统概念再到蜜蜂案例，构建层层递进的学习支架。 其亮点在于多模态输入与任务驱动结合，通过视频、听力、流程图等培养语言能力（如“delicate”语境辨析、完形填空巩固生态术语），借助蜜蜂案例的因果链分析提升思维品质，结构化活动设计助力学习能力发展。学生能在实践中深化语言运用与逻辑思维，教师可依托丰富资源高效实施教学。

Unit 5 A delicate world Starting out A delicate world delicate|ˈdelɪkət| easily damaged or broken =fragile made or formed in a very careful and detailed way the delicate watch (of colours, flavours and smells) light and pleasant; not strong a delicate fragrance/flavour How can we interpret the title? The interpretation of “a delicate world” fragile, easy to be damaged The Earth’s ecosystem is easily broken by human activities. The balance of nature is weak and easy to destroy. made in fine, detailed ways The food chains, water cycles and climate systems are perfectly and precisely formed. All natural parts work together in a careful, complex way. light and pleasant The world is filled with gentle natural beauty, such as light flowers and clean fresh air. Activity 1 1. Are humans part of Earth’s ecosystems? why? 2. In what ways can humans affect ecosystems? words and expressions: tundra /ˈtʌndrə/ 苔原，冻土 taiga /ˈtaɪɡə/ 针叶林 savannah /səˈvænə/ 稀树草原 grassland 草原，牧草地 prairie /ˈpreri/ 北美大草原 desert 荒漠 steppe /step/ 西伯利亚干草原 intertidal zone 潮间带 subtidal zone 潮下带 continental shelf 大陆架 deep ocean zone 深海区 estuary /ˈestʃueri/ 河口 deciduous forest /dɪˈsɪdʒuəs/ 落叶林 temperate rain forest 温带雨林 tropical rain forest 热带雨林 arctic ice pack 北极浮冰 wetland 湿地 marine mud flat 海洋泥滩 rickety /ˈrɪkəti/ 不结实，不稳固，易折断 4 5 Lead-in Watch the video and answer the questions: 1 What is the key message of the video? All the living things depend on other living things, so biodiversity is essential to ecosystems. 2 How did the speaker express the message in a simple way? He compared the ecosystem to the wooden puzzle game and the game of sticks. Ecosystems What does the diagram(示意图) show? What are the relationships between the living things? Read the boxes and pay attention to new words and expressions (Activity 5, P72). They are interconnected and interdependent. The diagram shows a food chain. dissolve v. 溶解 dissolved adj.被溶解的 prey on/upon sth: to hunt 捕食 prey n. 猎物；受害者 predator n. 捕食者 decompose v. (使)分解;腐烂 生产者 初级消费者 二级消费者 分解者 nutrient n. 营养物 nutrition n.[u] 营养 nutritious adj. 营养丰富的 8 Ecosystems Complete the passage with the correct form of the words and expressions (Activity 6, P72). absorb rely on fed on prey on break down release 9 Honey Bees Read the facts and then fill in the blanks based on memory. The honey bee has been in existence for _____________. A honey bee can fly as fast as _____________________ and its wings can beat __________________. In just one journey to collect pollen (/ˈpɒlən/) and nectar (/ˈnektər/), one single honey bee can pollinate (/pɒləneɪt/) as many as _________flowers. millions of years 24 kilometres per hour 200 times per second 50 to 100 Honey bee Listen to the conversation and choose the true statements. Bees are very important to our food supply because they provide honey. The bee population is declining. Without bees, humans would die out. All human crops depend on bees for pollination. If bees became extinct, other insects could pollinate enough crops. Humans are responsible for the decline in the bee population. 11 Honey bees Listen again and complete the flowchart. pesticides and climate change declining very quickly have fallen by 17% be unable to reproduce Other insects bees are responsible for pollinating about 70% would die out 12 Honey bee Look at the flow chart and summarise the main idea of each box. The problem/phenomenon The cause The effect on crops The effect on animals The effect on humans 13 Smart Expressions – P72 absorb v. 被吸引；专心致志 溶解态营养物 rely on feed on prey on decomposer 把……分解为 vegetable matter 被释放回食物链中 在林地生态系统中 take in 吸收；吞并；理解；吸引 be absorbed in sth./doing dissolved nutrients 依靠 以……为食 捕食；猎获 分解者 break down… into… 植物性物质 matter [U] n. 物质（统称） be released back into the food chain in a woodland ecosystem 吸收；理解；收容；欺骗；参观 14 primary consumer secondary consumer mammal n. 剩余物；残骸 fertilise v. Flowers are often fertilised by bees as they gather nectar. fertiliser n. 初级消费者 次级消费者 哺乳动物 the remains (pl.) of… 施肥于 使受精；使受粉；使受胎；使受孕 肥料 Smart Expressions – P72 15 Smart Expressions – P73 现存的，实际存在的 花粉 n. - 授粉 v. 花蜜 灭绝 依靠 作为原因；成为起因 ……的结合/混合 没有蜜蜂，庄稼无法繁殖。 弥补……的损失 夸张的 adj. 夸张；言过其实 v./n. in existence = existing pollen n. - pollinate v. nectar die out/become extinct adj. depend/rely on be responsible for a combination of _________ bees, crops _________ (be) unable to ___________. compensate for the loss of… exaggerated exaggerate/exaggeration extinction [U] n. Without would be reproduce 16 Lavf58.12.100 null 146280.0 $