按你的程序作了必要的几处修改:#include<stdio.h>#include<stdlib.h>#definePi3.1415927intmain(){doubleInput,ra,f;printf("Pleaseinputyournumbertocalcutionwhatyouwant\n\n1.Ball'sVolume\n2.SurfaceAreaofTheBall\n\n");scanf("%lf",&Input);if(Input==1){printf("\n\n\nV=(4/3)Pi*r^3\nPleaseinput'r'\n");scanf("%lf",&ra);f=(4*Pi*ra*ra*ra/3);printf("%lf",f);getch();}return0;}程序能够运行了:但是你的2.SurfaceAreaofTheBall程序还未加入。