5 Sweet Mirage

指导老师：姚红英

Put a lit candle behind a bottle. If you blow on the bottle from the opposite side, the candle may go out, as if the bottle was not there at all. Explain the phenomenon.

1. 怎么定义 a lit candle？
2. 这个课题，似乎实验容易做，理论上，如何着手？
3. behind需要有哪些限定？