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

2??????

3??????????

4??????????

5??????????

??6????8??? (??)???????8???????????????????????????????CT??????,??,????????,???,??????????

6????????????8?????????????????????,???????????????????????? ?????????

????????1978???????,???,????????????????(??)????????????????????????????????????????,??????????????????

????????,????????????????????????,????,????,????????,????????????CT????????,??

???,????????????:????????1?33??????19???????????????U???,???32?????23????;??????????????1????????44??????????,??????????????8????52??????????????????4?????????????????????????

?(????????????????)?(?????)

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

????????,?,????????????????????????????,???????????,?????,??????????(??????????)

?????:???