岛国无码免费不卡av,日本精品视频一区二区三区,91国产网站,99热久久精品免费精品,中文字幕丰满人伦在线,成人av高清在线,97av在线

The first is brewing pedometer by Italy's Leonard Da Vinci, but the earliest pedometer is in Da Vinci 150 years after the 1667 production. In the middle ages and modern times, not a pedometer is widely used, because people do not know its purpose. This shows that the invention of the machine is not as important as finding it for the use of human beings. The pedometer is mainly used for sports and walking pace analysis record. usually as a step by step pendulum principle, the use of mechanical switch detection pace increase, and with a simple counter. If the sloshing of these devices, you can hear a metal ball slide back and forth, or a pendulum swinging ring when the block. This mechanical pedometer has faded out of history, it is replaced by the electronic pedometer pedometer was first brewed by Italy's Leonard Da Vinci, but the earliest pedometer is in Da Vinci 150 years after the 1667 production. In the middle ages and modern times, not a pedometer is widely used, because people do not know its purpose. This shows that the invention of the machine is not as important as finding it for the use of human beings.The pedometer is mainly used for sports and walking pace analysis record. Usually as a step by step pendulum principle, the use of mechanical switch detection pace increase, and with a simple counter. If the sloshing of these devices, you can hear a metal ball slide back and forth, or a pendulum swinging ring when the block. This mechanical pedometer has faded out of history, it is replaced by the electronic pedometer