학생들은 시계도 봤다가, 눈도 굴리고 하다가 결국 궁금증이 생기겠죠. "선생님, 그걸 채우는데 얼마나 오래 걸려요?"
Students are looking at their watches, rolling their eyes, and they're all wondering at some point or another, "Man, how long is it going to take to fill up?"