用细铁丝做一个3厘米宽、8厘米长的框,在框的中间搁一根直的铁丝,不要固定。把框水平地轻轻浸入肥皂水中,铁丝框上便绷有一张肥皂膜了。拿针刺破框一侧的薄膜,铁丝便会被另一侧的薄膜拉过去,一直拉到框的那一头。液体的分子相互之间有很强的内聚力,肥皂膜的弹性几乎 Use a thin wire to make a 3 cm wide, 8 cm long box and place a straight wire in the middle of the box, not to be fixed. Gently submerge the box into soapy water, and a bar of soap is stretched over the wire frame. Take a needle punched box side of the film, the wire will be pulled over the other side of the film, has been pulled to the end of the box. Liquid molecules have a strong cohesion between each other, the flexibility of soap film almost