????:1???????:????

2?????????

3?????????

4??????

5??????????????

????????“????????,??”,????????????“??????????”,?“??????????”???????????,??????“4S?????”????????????,??“???????????????”????,????????????????????????????“??”,?????????????????,??50??,????????,???“????????????”??????,?????“???”?

??,??“??”??????????????,???????????????????“??”?????????,????,?????????,?????????,???,???

???????????? ??????? ???????????????????

???:????????????