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

2???????

3?????sn??

4???????????

5?????????

??????12???????20????????????? (??????????????? ??????????????????)?????????????20??,????,????19??????????????????????????

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

???????,????????????????????,????,?????????,?«??????»,???????????????????????????????,????,????????????

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

?????????????????,?????????????10????????????????????????????,???????????????,???????AIS??????,????,?“?????????????????”???????,??????,??????????“????????????????”?????????,????????????,?????????,?????????????????????????????????,????(????) ???????????:?????