Bridgesarebuil的精选

问题详情：动词应用根据短文内容，用括号内所给动词的适当形式填空，必要时可加助动词或情态动词。Bridgesarebuiltformanyreasons.Somebridgesarebuiltsothatcars  1  (cross)overrivers.Othersaremadefortrainstouse....