一、填空题（每空4分，共48分）：1．若两圆有4条、3条、2条、1条或0条公切线，则它们的位置关系分别是．＊罗2．若两圆的圆心距是互5，且两圆半径是方程X’－I3X＋22一O的两个根，则外公切线长为，内公切线长为．；3．两圆半径之和是12，差是几若外公切线长是8，则圆心距是； First, fill in the blanks (4 points for each space, a total of 48 points): 1. If the two circles have 4, 3, 2, 1 or 0 common tangents, their positional relationship is respectively. * Luo 2. If the circle’s center-to-center distance of the two circles is 5, and the radius of the two circles is the two roots of the equation X’-I3X+22-O, then the tangent length of the grandfather is the length of the tangent. ;3. The sum of the radius of the two circles is 12, and the difference is several if the tangent length of the grandfather is 8, then the circle center distance is;