第4章（第3页）

请退出浏览器阅读模式，否则将导致章节内容缺失及无法阅读下一章。

è???°±??ˉ??·?￥3???????????-?3¨?????????è???§??·§????1?è???￠°??????

????2????????¤?èˉ′???

?????a?°??????????????????μè???o?è?????è????????

???è??é?¨?????￥è???￥??￥???oé|????è??????oo?°±??′?o??????￥?????a???è????????????????-?????ˉ?￥???3é??????????????

a???￥??-??-???????????o??????°????o????a??

è?????è????a?-￡???????a3?|????è￠??????￥?o???a????o????

è???¤????é¤??????????

?￥??￥????è?????è???ˉ?è·?é????????è??????????????????°±è??è???o-?·±??????????1?????????¨?￥1èo?????μ?è?????

??????????-·?-?????????????è????°è°·?o????

è???°±??ˉ?￥3??????é-??????§???

???????ooé?????è￠??￥1??????????????￠?￥1a?|a?|

?ˉ???????è·?è???o-?·±???????o??1′?????¨è????aè??????1??2??????￥???è??è???§???￠?￡°???èˉ-???

?????￥??oè???o-?·±???é??????°???′?°±??ˉ??￥è????¤?????????

????-¤?ˉ????è????￥é???-￡è￥???±????????ˉ???è?a?·±??ˉ?o?????1?é????1è???o-?·±???é???oo????????????

??ˉ??°??¨???????????￥é??????????￥???????1???ˉ??ˉ??￥è???1????è???o2?????????

é??????????a??¨?o???????è§?é?￠?????o???????°±????o??o????è???o??1′????°?????????????

??????é????????è?|??????

???è??????3????èˉ′????ˉ1?????·?￥3????????ˉ??????é????????

???????????¨?????°?¤1?o?????o???????è??????????????

???????§???????è????????????21???è????????

???????o?????￡°???????????′?·′èμ??′§è·??????????é?′???

?-????????????o??￥???????????°???????oo?????????é??è????°?o????èo???????

è???ˉ?????????￡èˉ???￠é?????a???|?èˉ-??????è??????o?????????ˉa?|a?|????-??o???§???a??

请退出浏览器阅读模式，否则将导致章节内容缺失及无法阅读下一章。