A diet deficient in vitamin D may cause the disease rickets.缺少维生素D的饮食可能导致软骨病.Richs'dog may receive the milk that a poor child needs to avoid rickets.富人的狗可以得到穷人的孩子为了避免软骨病而必须饮用的牛乳.Rickets can cause bone pain and weakn...
Plains, plateaus, and mountain ranges are major landforms.平原 、 高原和山脉都是主要的地形.Landforms of topography, vegetation and climate are influential factors in formation of soils.地形或地形学 、 植被和气候都是对土壤形成有影响的因素.Water and soil loss is...