考前复习! A) if(x=0;) printf("%f",x); else printf("%f",-x); B) if(x>0) {x=x+1;printf("%f",x);} else printf("%f",-x); C) if(x>0); {x=x+1;printf("%f",x);} else printf("%f",-x); D) if(x>0) {x=x+1;printf("%f",x)} else printf("%f",-x);