miss green was going to give a lecture on monday afternoon. yet on sunday night she was told that she had to go to an important meeting the next day at exactly the same time. “no one can be in two places at once. what shall i do?”she thought. but soon, she had an idea.

　　at five to three on monday afternoon miss green went along to the lecture room. there were about 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 green explained that she had an important meeting. “however,”she went on, “although 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.”thinking that she had settled the matter, miss green turned on the recorder and left.the meeting finished a little early. miss green decided to go back to her students. she stood for a moment outside the lecture room, listening to her own voice. then very quietly, she opened the door. to her surprise, the room was empty. as she looked around, she saw a number of recorders----all“listening”to her lecture.

　　“well,”she thought,“if i can be in two places at the same time,why can't they?”