我们都曾有过这样的经历:小时候,一不小心把鞋带系成了死结,我们总会哀求妈妈帮帮忙,而慈祥的妈妈也总会蹲下身子,边解死结边叮咛:“记着,以后要系成活结。”长大了,手也巧了,我们学会了做很多很多的事,更学会了系各种各样的结。可是有一天,忽然发 We have all had this experience: When I was young, I accidentally tied my shoelace to a knot. We always plead with my mother for help. The kindly mother always squats down and dies. In the future, it is necessary to tie a knot." When we grow up, our hands are also clever. We learned to do a lot of things, and we learned a variety of knots. But one day, suddenly made