#全国公共英语PETS-2精品阅读56 搜索结果
Justlikepeople,starsalsohavelifespan.Astarkeepsthesamecolorandshapeformostofitslife.Butwhenitgetsveryold,itswellsintowhatiscalledaredgiant.Afterreachingthisstage,somestarsbegintocooldownandgrowdim.Otherstarsex
