expansionsn.扩展（expansion的复数形式）expansionn.膨胀；扩展；扩充expansion project扩建企业expansion bracket伸缩架expansion fashion膨胀方式expansion bushing膨胀衬套expansion program扩建工程expansion muffler扩张式消声器Expansion of base扩底expansion pattern扩张方式expansion mapping膨胀映射expansion theorem展开定理