tractors拖拉机tractorn.【C】拖拉机；牵引车tractor-propelled harrow机引耙tractor and semi-trailer拖拉机和半挂车组成的货运车Tractor transmission system拖拉机传动系tractor cram-shell bucket曳车蟹壳桶tractor trailer type aerial牵引挂车式云梯车tractor-trailer engagement牵引车与挂车的连接tractor rocket escape system牵引救生装置tractor running on the roads道路行驶拖拉机tractor type universal joint凸块式等速万向节tractor-mounted distributor机挂撒肥机