这起抵押合法吗？编辑同志：我为１８岁的儿子买了一台小四轮拖拉机及挂车，希望就此拴住儿子的心，让他从事正当经营并为以后成家立业打基础。谁知在我最近外出考察新的养殖项目时，不争气的儿子与人赌博，一夜间输了６５００元。债主要债，扬言３日内如不还清要将他“摆... This mortgage legal? Editor's Comrade: I bought a small four-wheeled tractor and a trailer for my 18-year-old son in the hope of catching my son's heart, letting him engage in proper business and lay the foundation for his future career. Who knows when I recently went out to inspect the new breeding project, the angry son and people gamble, lost 6,500 yuan a night. Bonds the main debt, threatened to not pay off within 3 days to "put ...