ass日本风韵熟妇pics男人扒开女人屁屁桶到爽|扒开胸露出奶头亲吻视频|邻居少妇的诱惑|人人妻在线播放|日日摸夜夜摸狠狠摸婷婷|制服 丝袜 人妻|激情熟妇中文字幕|看黄色欧美特一级|日本av人妻系列|高潮对白av,丰满岳妇乱熟妇之荡,日本丰满熟妇乱又伦,日韩欧美一区二区三区在线

According to the technical measures for reducing the mechanical soil compaction, all terrain adaptive locomotion chassis for farmland with ultra-low pressure tires was proposed as solution scheme based on the conventional wheeled locomotion mechanism. The mechanical model between the tire and ultra-low pressure was established. The terramechanics of all terrain adaptive locomotion chassis for farmland which used ultra-low pressure tires was anayled. At last, compared with the existing four-wheel drive tractor, it was proved that all terrain adaptive locomotion vehicles for farmland could reduce the mechanical soil compaction and met the modern agriculture’s need with well performance and tractive effort.