题目

现给出以下几个命题：（1）长度相等的两条弧是等弧；（2）相等的弧所对的弦相等；（3）圆中90°的角所对的弦是直径；（4）矩形的四个顶点必在同一个圆上；（5）在同圆中，相等的弦所对的圆周角相等.其中真命题的个数为（     ）   A．1              B．2               C．3                D．4 European football is played in 80 countries ,______it the most popular sport in the world A. making    B, makes    C. made    D to make