1. PPI\practice1\practice1.c ......\.........\practice1.cif ......\.........\practice1.dxs ......\.........\practice1.mak ......\.........\practice1.sdl ......\PracticePPI\PracticePPI.c ......\...........\PracticePPI.cif ......\...........\PracticePPI.h ......\...........\PracticePPI.mak ......\...........\PracticePPI.sdl ......\practice1 ......\PracticePPI 1. PPI