????????????????????????????????????????ɡ?????
?????????????????????????????????????????????????·?????????????????????ο?????????
?????????????????????????????60???????????????
1. ?????:??????5??????????1????????1??????????5??(????12?????
2. ?????:????5????????1???????1??????????1?????????1??.(????9?????
3. ?????????1????????1???????????1?????????1??????????4?????
4. ????????????5????????????5???????????5???? ??????15?????
??????????12+9+4+15=40???????????60????30??????????10?????40??
70????80??????????????????80??????????????????????
????и?????????????????????????ο??￡???????????????
??????????????????彡????
????????????????????????????????????????40407???????40407????????
