I hope you can help me ____ ____ ____ the matter as soon as possible.
读图,甲点所在的经纬度是( )
已知⊙O与直线AB相交,且圆心O到直线AB的距离是方程2x-1=4的根,则⊙O的半径可为( ).
已知i是虚数单位,则 3-i2+i= ( )