A:九•一八事变
B:一•二八事变
C:七•七事变
D:八•一三事变
下列说法正确的是()
对60个数据进行处理时,适当分组,各组数据个数之和与百分率之和分别等于( )
European football is played in about 80 countries, ____ (make) it the most popular sport in the world.