定义网络覆盖范围\cover.cpp
................\Debug\cover.obj
................\.....\cover.sbr
................\.....\sub2.bsc
................\.....\sub2.exe
................\.....\sub2.ilk
................\.....\sub2.pch
................\.....\sub2.pdb
................\.....\vc60.idb
................\.....\vc60.pdb
................\define.h
................\function.h
................\point_description.h
................\sub2.dsp
................\sub2.dsw
................\sub2.ncb
................\sub2.opt
................\sub2.plg
................\Debug
定义网络覆盖范围