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

2???????

3?????????

4????app???

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

??????????????2????21????? (????? ??????????????)????????????21????????,??,???????“?????????????”??????????,?????????,?????

2??21?????????????????,“?????????????????”?????????? ? ?

??,???????????,???,??,??????????????????,??,?????????????????????????????,??,???????????????,???????????,????????,??

???,????,??????????,?????????????,?????????????,???????????????

??????????????????????(????)???????????,????????????????,?????“????????????????????????”???????????,????????????20????????????,??????,??????????????,????????,???(??????????)

???:????