file:1414文氏图.mp4 file:1413三人比较---.mp4 file:1411分给两个相同对象.mp4 file:5411最佳会合点问题.mp4 file:5409直线分图面2.mp4 file:4413数字计数中的重复数.mp4 file:4412排列组合辨析.mp4 file:4411数阵图，重数分析法.mp4 file:4410三角形面积反求.mp4 file:3407几何图形剪切.mp4 file:6201抽屉原理5.mp4 file:6119等高三角形比列关系.mp4 file:6118浓度十字交叉法.mp4