Alex:no,you tell me what shape
教授:ok, it is four corner, now can you tell me what color?
Alex: what matter?
教授:Alex it is wood,can you tell me what color?
Alex: how many?
教授:well, there is one toy here, come on Alex, you gonna tell me what color。
Alex: no, what shape?
so the professor decided: "ok, I had it, I am going to walk away and give alex a timeout". so the professor start to walk away