?? ???????????????????????? ????
![](https://image.chezhanri.com/2019/0625/20190625101925644.jpg)
????:1????????:???????
2??????????
3?????????
4???????
5???sn??????
??7??????????30??????????????????? (?????????? ??????? ???????????????)????????????????7????30??
??????????????????:???,??,?????????????,?????????????«?»???????????,?????????????????????,??????
?????????????????????????:????????,???????????????????
????????????????????????,????????????,???«??????????????????»???????????????,?????????????????(?) ?????:???