有两列火车,一列长130米,每秒行23米。另一列长250米,每秒行15米。现在两车相向而行,从相遇到离开需要几秒钟?-O/d.f,z'm;}1a7]3d
算式:提示0M4d*t.?,K6r,{.w(X8w;B3s9?;^+J7l)t7Z-O/d.f,z'm;}1a7]3d
答:从相遇到离开需要4K:A/a-c秒钟。-O/d.f,z'm;}1a7]3d