DME的基本工作原理是什么？
参考答案：
利用飞机和地面测距台之间的无线电波往返所用的时间来测定飞机和测距台之间的距离。
句型转换。
1. I like winter best. (对划线部分提问)
______ ______ do you like best?
2. I think the weather is cold. (否定句)
I ______ think the weather ______ cold.
3. I like swimming very much. (同义句)
I like swimming ______ ______.
4. What about you? (同义句)
______ about you?
5. My favorite season is winter. (同义句)
I ______ winter ______.
