在下列语句中存在错误的是
A. int a,b;scanf("%d%d\n",&a,&b);printf("%d %d",a,b);
B. float a,b;scanf("%3.2f %4.2f",&a,&b);printf("%f %f",a,b);
C. float a,b;scanf("%f %f",&a,&b);printf("%f %f",a,b);
D. float a,b;scanf("%f %f",&a,&b);printf("a=%4.3f,b=%4.3f",a,b);
E. int a,b;scanf("%2d%2d",&a,&b);printf("a=%d,b=%d",a,b);