SORU: boş bırakılan yere parçanın anlam bütünlüğünü sağlamak için getirilebilecek cümleyi bulunuz
As anyone who has sat through a lecture on a warm day knows, attentiveness and mental alertness can be hard to sustain. ----. Its counterpart is sleep, a state in which we continue to receive stimuli but are not conscious of them.