论文部分内容阅读
手提式自行车:日本研制出一种可折叠的手提式自行车,安有一个特别的箱盒,骑动时,它有保护传动系统的作用,折叠后自行车全部部件可装在箱内。手摇水上自行车:苏联不久前研制出一
Portable Bicycle: Japan has developed a foldable portable bicycle equipped with a special box that protects the drive system when riding. All parts of the bicycle can be folded in the box. Water bike on hand: the Soviet Union recently developed a