?????

???????????????50%????
??
1????????????????????????????????????????
2???????????????
3??????????
4.50??????? ?????????????????????????????
5???????????????60%????8%?????40%???????50%??5%
6??????????????????????????????????????
7??????


???????????????????????40???????????????F??????????????????????????????


????????????????????????? ?20-30?20?6???10??3????2 ??10??6???30?10????30??30???10??10???????30?