How many of you have a written contract, stuck with a magnet on the fridge, telling you when you're supposed to tidy up.

有人写过协议吗,在冰箱上贴个磁力贴,规定好什么时候该谁打扫房间

耶鲁公开课 - 博弈论课程节选

And if you use this little magnet you can draw a mustache or hair, or eyebrows or whatever on this particular face.

如果你想使用这小磁铁,就可以画个小胡子,或者头发或者眼眉等。

哈佛公开课 - 计算机科学课程节选