老师
Hello, everyone. Welcome back. Do you remember what we Learned last lesson? Yes, we Learned how to be an inventor. Did you ever try? After class, I searched the internet and found many inventions in our lives. Today, I'll introduce one of them to you.
学生
当你看到了一个陌生的地方，你是如何辨别方向的？有的同学可能会说是靠太阳的位置来辨别的，有的同学会说晚上还可以看星星来辨别。今天我就给大家介绍一种跟辨别位置有关的发明。
老师
look at the pay。 Picture. Can you guess what is it? Yes, it's the GPS. Let's read 1A and then you can know more about it. Try to answer the questions while reading.
老师
How did the early explorers know where they were? What's the disadvantage of using the stars as getting marks? Where are we? Where are we? That was a big question when we first explored our world long ago. The early explorers found that the stars in the sky were good guiding marks. Using the stars, they could find out where they were and in which direction they were going. This method worked well at night, as long as the weather was good and the stars could be seen. But it didn'查看隐藏内容