Miss Evans was going to give a lecture   on Friday afternoon. But on Thursday night she was told that she had to go to an important meeting the next day at the same time. "No one can be in two places at the same time. What shall I do?" she thought. But soon, she had an idea. At five to three on Friday afternoon, Miss Evans went to the lecture room. There were twenty students waiting there for her. "I'm sorry," she told them, "I won't be able to give my lecture today." The students looked surprised. Miss Evans explained  that she had an important meeting. "However," she went on, "though I can't be with you myself, my voice can." Then she put a small tape recorder   on the desk, "You see, I've recorded my lecture and you can listen to it without me." Miss Evans turned on the recorder and left. The meeting ended a little early. Miss Evans decided to go back to her students. She stood for a moment outside the lecture room, listening to her own voice. Then quickly, she opened the door. To her surprise, the room was empty. As she looked around, she saw a number of small recorders "listening" to her lecture! "Well," she thought, "If I can be in two places at the same time, why can't they?" When she returned from the meeting, Miss Evans found  _  her lecture.
all her students listening to every student recording her students had left some recorders recording some of her students listening to