Picture an empty wine bottle with a cork secured at the top in the usual way.
设想有一个空酒瓶，瓶塞以通常的方式固定在顶部。
Inside the bottle a metal ring hangs suspended by a string.
瓶子里挂着一个金属环，用绳子吊着。
How is it possible to make the metal ring drop to the bottom of the bottle without touching the ring, the thread, the cork, or the bottle while leaving the cork in place and intact?
怎样才能使金属环落在瓶子底部而不接触环、线、软木塞或瓶子，同时使软木塞保持原位和完好无损呢？
Answer
答案
By using a magnifying glass and the sun's rays you could burn through the string and consequently cause the ring to drop to the bottom of the bottle.
用一个放大镜聚焦太阳光，就可以烧断绳子，从而使金属环掉到瓶底。
