Unit 7 Cross-curricular connection课件 2025-2026学年沪教版八年级英语下册

Space exploration Cross-curricular connection Pre-reading Do you ever go on road trips with your family? How do you find your way? Do you use any map apps? How does the app help you find your way to the destination? The app shows us where we are. It gives us the fastest way to get to the destination, and it also tells us where to drive and when to turn. The app also shows us traffic in real time. How does the app know where you are? It uses signals from satellites in space. navigation /ˌnævɪˈɡeɪʃn/ 导航 satellite /ˈsætəlaɪt/ 卫星 Discuss in pairs. How does BDS Work? Let’s explore the science behind it! How BDS works What is BDS? BDS, officially known as the BeiDou Navigation Satellite System, is one of the global navigation satellite systems. How does BDS work? BDS is a group of satellites in orbit around the Earth. Each satellite sends radio signals to the Earth with information. The signals answer two important questions: “Where in space is the satellite?” and “When did the signal leave the satellite?” The radio signal travels through space at the speed of light—that is 299,792 kilometres a second! Back here on Earth, your phone receives the signal and compares it to the exact time of arrival. The phone then calculates how far it is from the satellite. One satellite is not enough. Your phone needs information from four satellites to calculate your location. It does this all the time. So, when we use a BDS device, we won’t get lost. What’s special about BDS? We can also use BDS for two-way communication. In areas without any mobile network, people can send text messages through BeiDou satellites. How do we use BDS? If your phone supports BDS, it will automatically pick the navigation system with the best signal at the time. Can we use BDS outside China? Yes, we can use BDS outside China, but its accuracy is higher in China and the Asia-Pacific region. BDS = BeiDou Navigation Satellite System It is a Global Navigation Satellite System (GNSS). It helps us find our location anywhere on Earth. Read the definition. What does “BDS” stand for, and what is it? What is it used for? While-reading–What is BDS? Where are the BDS satellites? 2. What do the satellites send to the Earth? 3. How can we receive the BDS signals? 4. How many satellites does your phone need to calculate your location?    They are in orbit around the Earth. Radio signals with information about their location and time. We can receive the signals with a phone or other device that supports BDS. Four. Look at the text and answer the questions. While-reading–How does BDS work? 1. What is special about BDS? We can use BDS for two-way communication. In areas without any mobile network, GPS only allows you to receive signals, but people can both receive and send text messages through Beidou satellites. Example: The engine on a ship breaks down when a fisherman is out at sea. There is no mobile network, and the ship’s radio doesn’t work. With GPS, the fisherman can only get his location, but he cannot communicate. If he has a special BDS device, he can send an SOS message with his location. He can also receive messages with the BDS device. 2. In what situations might this feature be useful? While-reading–The special features of BDS In groups, discuss how BDS helps these people. Farmers Taxi drivers / Delivery drivers Scientists Pilots / Sailors You (Walking, biking, finding friends, …) Choose one or two of the groups above. How does BDS help them? How can BDS help you? Share your ideas with the class. Post-reading A timeline: the development of BDS Time Event 2000 The BDS-1 (experiment) system was completed around 2000 and began providing limited regional navigation services in China. 2012 The BDS-2 system was completed in 2012 and began providing regional navigation services in the Asia-Pacific region. 2020 The BDS-3 system was completed in 2020 when its final satellite was launched. Its navigation services became available all over the world. Now BDS is used by millions of people worldwide for navigation, timing, and many other services. Post-reading 评价内容 评分（1-5） 1. 我能理解北斗导航的定义、工作原理及应用。 1 2 3 4 5 3. 我能绘制北斗导航工作流程图并进行解释。 1 2 3 4 5 4. 我能关联跨学科知识，理解北斗导航的工作原理。 1 2 3 4 5 5. 我能认识到北斗导航的价值，增强对中国科技成就的认同感。 1 2 3 4 5 Self-assessment Homework Each group chooses one of the following topics (or another topic related to China’s space programme). China’s manned space programme China’s lunar exploration programme Long March rockets series Tianwen Mars mission Task: Find information about the topic and make a simple timeline about it. Resources: Visit English science or news websites. You may use AI tools to help you find information and organize your ideas. hit v. 碰撞；撞击 The car hit a tree during the storm. adjust v. 适应；习惯 It took him a while to adjust to the new school. naked eye 肉眼 The planet Mars is very bright and easy to see with the naked eye. point n. 时刻；阶段 At that point, she was too tired to continue, so we took a break. select v. 挑选；选拔 The teachers will select one student from each class for the competition. 感谢观看 THANKS Blues 132158.55 1802.4482 3448.1682 2403.2659 2925.717 $