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

???2???????????????????21???????????? ??21??????????,?????????????????????,?????

??,2???????????????????20???,??????????2?C-208???????1?N-22??????,??????????????

?,?????,?,???????????????????????2??????????????????18??????????,?????????1?C-208???????,?????????,218??920?,????????,????,????????,???????????????“????????”?????,?????????????????????????????????,??????,?????????(?)