英汉例句双语例句Objective To observe the expression of pulmonary surfactant-associated protein D (SP-D) during human fetal lung development.目的观察肺表面活性物质相关蛋白-D（SP-D）在人胚胎肺发育成熟过程中表达的特征。pulmonary surfactant protein d更多例句词组短语短语pulmonary surfactant associated protein d 表面活性物质相关蛋白dpulmonary surfactant protein d更多词组