老 狗 分享
星期天早上快樂的數學課 (devil) https://images.plurk.com/3431095_96655e067f26cce41f51c38cfd3ee531.jpg https://images.plurk.com/3431095_679b0c9520dff6f46bbed10903f559fe.jpg https://images.plurk.com/3431095_3720406eede1e6fca1a53a04845bb67d.jpg 雖然還不大會數... :-)