SORU: boş bırakılan yere parçanın anlam bütünlüğünü sağlamak için getirilebilecek cümleyi bulunuz
How common are other civilizations in the universe? This question has fascinated humanity for centuries, but so far no definitive answer has been found. ----. Chief among these is the confirmation, after a long wait and several false starts, that planets exist outside our solar system.