??????è?????????????????????°±?????ˉ?????????????1′?????????????????o??′?????o?°???????????????????
?ˉ1??1?·2???????o????????????·??????è???°??2????????????????????1???a???????ˉ1??1??¨??·???
è????????????o?????????????a????¨?o??¤??°????a??
a??0。5%???é¢???°??oè????????è|??????¨1%?·|??3???a??
è?????è??????1???????????o?????????′??¥???èμ·èo??-????????????????????????????
?·¥??????????o??????????????????????è°??????′??¥?????o?o???????é?¢???é¢?????????????
a??è??è????a??ˉ???é?¢???????????¨????|?????ˉ1??1?????§??-??????????·¥?¨?è???o|?1????è¢?è??èˉˉ???è???????????è′1??¨é??????????¨???a??
????ˉ?èˉ′?????¥èˉ????????????????è??è?2?°±???????????????
????????°?¥1???????????£?????ˉé???????¥é??èˉ¥èˉ′????1????
è?????è?¤????????????????????????????o?????¤aé?3??′???
è????ˉ???????1???ˉ??§??¨???????ˉ????é????°??|????o?é?????è????·???
?|????????????o?o?é??é¢????é?£?°±?????ˉèμ??????????è???·2?o????
?????????????????????è????¨??????è????????a???????ˉè′?è′£?oo?????????????ˉ1??1è°???¤???a??
a???????????????????ˉè??è???????????è???????????è′?è′£???a??
?????′??¥???????o??????????è?????
??????èˉ′è???§??o????????????????????°±?????ˉ????????????????1????????????????
è?3?°????è???????????
è?????????????????è?????????????a??????????????μ??????
a??è|??????????a??
?????ˉèμ·?????????????o?????????a?¤§?¤§????????????a?????????¥?????????????????·?é¢?????ˉ1??§???a??
??????????????????????°±è¢??°?????o????
a??è??????????????è°??|¥?o??????????50??????a??
???????????′???????o????a???¥???????è????????a??