births造句
intervalsbetweensuccessivebirthsTheyalsousedforcepsfordifficultbirths.theproportionofbirthstothepopulationThenumberoflivebirthsneededminimaladjustment.Naturalincreasesimplymeasurestheexcessofbirthsove...
intervalsbetweensuccessivebirthsTheyalsousedforcepsfordifficultbirths.theproportionofbirthstothepopulationThenumberoflivebirthsneededminimaladjustment.Naturalincreasesimplymeasurestheexcessofbirthsove...