第章 三大难题（1 / 2）

PmMvPA2CgOOwvOSEr+icveSlt+WTveS0leaTveS7uOSnpOWkuOS5r+WavOSUp+W4uOWUp+WCuOWNk+WxveWljua0m+eGsOW5gueCp+iWiOa3u+SEr+iEmue5peWMvO+8r+WGoumUp+WCuOWAneeooeiju+SQkueQkueOnealn+e7oemMvO+Kg+aHnOm6uOSnpOW9g+m6uuSWu+S2heWMvO+yiei4hOiQkueQkueOneaLnOe7oemgl+aog+myueWnuueFjuWNveSkuOSlgeWytOiMkuWfkOWMreaRuuSGuuSkmem6h+WAuOSAqOikreY+Yzw+Yy88DZ2A4oG874+E5qG75rq65KS75L6a6Yi+5Yy876q45Im45K+Y5rGw5ZmV54C45I2i55ya6YSa54uF5Y245IyA6LuU5pGd5q245I6f5Y+x5b6Q5bqM5bqM5Yy875y65aOt5rqM5ZSn5bqM5Zud5bGK6ISa56O06Imc5p+c5Yiu5Ymc5pi/6Iy874S754+w5byv5Yai6YSa55y95KW35YG/6IaL5pGd5q245I6f5YK45aiF5bmt55+757q45Jy95JyA4pq877Sv6LGw5aWd5oq45Iy875Sw5qKu5aGy5rSN5ZCS55CS546d5j5jPD5jLzwNgoDjna/osq7otq7lurrkqa7ojbjkvYPojbjkrq7omrzkrbjll4jltoTnopfmlKfluLjllKflgrjljLzvgorovKTnhJrniZzmlLrlupzlmK7lr5jmn7nktoTnk73ljLzvv4rli4nmhJrnt6/ogILpqrjkhrrkmoHlkJLnkJLnjp3mua/ljIDogKjokY/ljrrkpYDmiZzmobLmtrnlsJLpvZnnnYDigoDjpY/lpLjksq7ov5XpqIPpjp3mt6/onIDiPmM8PmMvPA2fvO+Emueum+equOSZv+iwiOW+vuizg+axsOWNuOSMvO+AseWEmuext+aIueSjgumDuOWMvO+Xu+S1mOmnpOWIueSjgum6h+WekOaLp+WAvOWOu+S2ruWnkOiCgOOcluWirOanpOWGmueIueSjgumMvO+dgOKeiuW5ieeLuuS5ieecgOK0r+icnuaCpuWwkum9mec+Yzw+Yy88DYKA46OP5biX6ZOB6YC45I6Q5YCc5q+Y5oaw5bCS6b2Z54y875uK5bq45L2D6KCX5rqk56ih6K6h546Y5rqM5Zud5bGK6IGA44S754+w5byv5Yai6YG/6IaL5oK45b6Y5o6Y5oi+5bq45KCb5Yy875ii6a6X6bOG5aOn6IyS5YaQ54Sk5bqc5bCO56+Y5rGw5a6u6Jq85Kmk5Yq75Iq45J6u5Yu65IKA442J5aKd6bCS6b2Z57CI5YaR5r2D6Yi754Cc5oy875ii6b6a6T5jPD5jLzwNgoDju7PnlIHohJrnlbznh7jknbjkg43lqJzlmK3ltq7llrjkn7vnoLzkjp/li4vljrjkjpDllbnljLzvkK3lsb3lgYzmo7vkiZzmkJrpkJrpjIfpnLjkoYLop6TlgY3ltoXlsIjlpZ/msrflsJLpvZnnpZ/mg7Dohq/lmKfnn5zmjYnlh7/oj7vnlLjkjIDojLzvobHoua/lhJrnpIrmtZHlg7/lvrLnnLrlo63mgZznr5jmpZ3mkZDljLzvuI/lrIXlgrjlirjkurjknL3kjLzvp6TltJvmmKLprpfphJrnopvlhpvpm4rlqIrlsKLmupzmm53lsYroPmM8PmMvPA2CgOOBgOaooeiuoeeOmOaJnOahsuaIu+eLp+WGi+aNuOSOuOSGi+aVuuWwiOWMvO+fkumsi+eJnOaFg+a1uuWRp+W8sOW5r+Wgm+WfjuW6uuSquOS6uOSgm+WSgOWNj+WMvO+fkOWMreaRuuSEmuemuuWBgOasoee6vOWBjOatuOScveSlt+WBv+iGi+aquOS0leaonOWOuuSzh+iCgOOjj+W+neahsua9g+m0pOWjgumMh+mBnOeOuuSzh+iMvO+BjOagiuWHu+eEu+equOSapOWJreeavOSPjeWZleabveSBnOeMkuWAseWZleYul67lgZzniZzmmL/ojLzvjInnnJPpka3nurvlpI/lpIrmnb/khJrnkY/lgaLpgLHlqYnnh5bmgZzniZzmtbrlkaflvLDlPmM8PmMvPA2CgOO5r+WNieaCoOWgpeewluaPveSdv+SpiuWuuOWlr+iUuuWMvO+2ruWnkOiOuuSgg+aXj+W5peWlneaLnOeBgOinkOionOW9g+ivj+WfvO+CoOWgpeeJhOiXjOWnkOiDvOW+lOa2ruWnkOiNnOa0r+i9u+Sruui8r+WGoumCuOWlu+S9g+ivj+WIueSOgOa5peWUgOKUgOK+mumIvuWEmuefnOeAqOiMgOi5peWonOWhruiwvOSMvO+HluaLuOSgl+afueSOkOWLueSMvO+UuuWUreehsua5peW2l+aTveWMvO+agOmfsua2ruWnkOiOuOSljua0l+m7s+ezheWEmueQreWsheWJuOSnkOiHv+iagOm5ruWziuiFouapruiwkum9meehrOaKuOSMvO+0r+iapOWFv+WNuOSEpOWVveSonOW+mumCoOWgpeewlua2ruWnkOg+Yzw+Yy88DYKA47Cc5aiU55q45KW35bq45LmJ5rmJ54yH6YGc54+7542J5bS55Zqk5aic5bK35YaI5aiD6a245LaF5Yy877Cc5Z+c5aGC6KWF5Zq85JSn5ZGd5qm65DY3hJrniZzmpYvmopvlhpvpm4rlqIrlsKLmupzmm53lsYrouI/lrIXlgrjlirjkm7zvtbrlkaflvLDlhJrnso/lho7ltLnlmqTlvpnnpLjkm7zvgqDloKXnsJbmtq7lp5Domrzvh4zmr5jmuYLnvprpp6Tlibjkh4zmgInmpYHlsrToPmM8PmMvPA2CgOOmuuWbv+iTveS0leaNk+WxveWMgOiil+abnOaCp+irsei5iueBgOO4ueWlvuSYreWDv+W7uOSauOSGiOWog+m0h+i8r+WMvO+GkOeEpOWwnOWhu+aGnOW2l+aKj+WqnOa9g+mYoumul+m5gue+mumnpOWJuOSRneatuOSOn+WvmOaJuOSbvO+/iuWYvOSEmuefhue0pOWwnOWBgOO/ueWJhOi6uuSsu+SWu+SolOeQv+iGiOWFheW9g+ihsuaMvO+xpOW6vOeGkOehrueXv+WMkOWBgOiog+myueWBgOi/uueMuuS5r+WvmOaMuuSbvO+6ruiGiOiBtea7uOSQiOaiveWMvO+lnea3teiGp+iNh+minemoheWcveSlt+WBv+iGi+aRneatuOSOn+WGsOWJnOahsuaMh+m6jOWMvO+NveSwiOWNuOSoiuWRj+WgvOSjruWfnOaNieWvmOaAuOSavO+ztuiNuOSinem5luaJuOSonOWYreWKuOScveSlt+WBv+iGi+aRneatuOSOn+WonOW6jOWbneWxiuiar+imneWlgeWytOg+Yzw+Yy88DYKA46iK5aui6KWt5qWt5o6Q5b2Q6KWt5oC45Iy877uO5Yq45Je+5Zel5Y2F6b2D6KGy5r2D6Zat57mv5YyS5b2W5qqO5oy874ek5YaH5YaQ54O/5YSa55e75Kyh55OJ5o+55Lq856Kd6bmW5pii6a6X6bmC576a6bmC542H6aic5Yy874q45JCt5bmC57CI5ZOK5qGy5pi/6Ia95JuK5aqK5Ya65JqB5Z+c5o2J5Y6Y5rSv6Iy876O06KqH6Ii+5Z+55Lq65Lu75KO06IC45Kys57q45Jy95Iy876ek5Yi+5ZuK5YuO5Y295Kuc5o665IWx5Yi754un5a245Jy95KW35YG/6IaL5pGd5q245I6f5bqM5aq45JS65Kic5bqM5Zud5bGK6KSu6L+J5qWB5bK06D5jPD5jLzwNgoDjh4Hphb7lhJrnh7/ol4/lq7rkobLmvYPprbjml7/lp5DojYnli7nkr5jmmb/ojLzvtKTlt7XonYDiv5XpgrjlvZnnhJrnrJXmirDlnIDipbvktoTnhbHljLzvlLDmoq7lkY3lprDon7nkna/otK/ojLzvvJznuqHpiZznjr3kjYnlop3psJLpvZnnqJzlirvkgqbljLzvkYXmgajlhJrniIPnurzluLjlnp3psIjll4/ljLzvjpnooazmhrrkh5zpsbHlnpvlhrrkspXmq6Lol67nn7nkjLzvoYrljIHov5XpuozliY7mv4vmq6LoupfmtIXlrYPpho7lj7vnlIDilIDipYHlsrToPmM8PmMvPA2CgOOBgOaooeiMkuWEr+i5ieaRiOaqh+i6jOWwnOWbv+iOkOWvmOafueSeruW2heWMvO+AqOiRj+WcuuWjrea5luawnOWooeiju+SlgeWytOiAneeljuY+Yzw+Yy88DYKA44mt54mt57Si54Cd54245L6J5p+55IGw6Jii6a6X6Y615o+754mc5qGy5oGA46+v6JmU6a+K54245IGm6KqP5bq45KSu6Iy876a65YGA5rO55bq66JaP5YeH6b2D6Yy875uc5qCX5pSA6ZW75LCI5Z+E5o2B6a6Z5piR5Yu65J6K5YGA46iD6bK55Yq45KW75IGy5Zqk5YGN5Zub5YKA44Sk5auI5bCI5YG15qS65IGm6LSX6baX5rWu5oe/6KOt5o2P5Yy877eg5oC45L2D6Y+d5b2l5Ze+5bK55Yu45K+Z5oyD6Kek5Ze+5Ymn6Iy876eA5qiK5bu45IyS5YWD5oC/5omc5qGy5py95KW35Yy8772Q6I695JSw5quj5Yy876iK5a615oO/5bq65Iy875y95KiK5aek5Ymc5pq85L2D6K+P5aWd5ou45KWO5oy876G75o245IiD57q85Zy65aOt5oK45ZSn5YK45bCI5Yav6I+E5rK35Ye754S754Kx5bqf5Yuc57WG5YWD5oq45KKd6Y675KSu6L+J5p+55J+Q5Yyt5pG65D5jPD5jLzwNgbzvnYDitq7llrvksIjloZ3nkYjmsZLphojlgLjko4nmopXmu47ljbjksbDlu47ljbjktK/onIDigKjorInmurrkiZzmjLzvjb3kNzKJnOaxheWog+myueWBgOiXv+WMkOWBgOi/uueMuuSEmueinemHv+iynOmRneatuOSOn+WonOWMvO+hjeWTieawiOW+reeqnOaOu+SMvO+lnealu+SVjeWNkOWRnea7qemDuOWsheWqh+i1huWFg+a4keaSjualreadiOWujea5oOabvO+/i+anheeRh+mWpeWMvO+Rj+WnheeEteilt+WYkeWQiOaEu+ecveSlt+WRnea7qemEmueHoOaHjOaQiOaMruW9g+iqnOaMvO+soeewouefnOeoiuWJnOahsua4oOaDgOibvO+/heiOkOWCuOWoheWGuuSWi+amuuWLqOenpOWIvuWMvO8lMy40NYmc5qqP5bSb5oeO54G/6KyQ5oy87yU5Nbq45IW75IeO56a6576t55Gd5q245I6f5Y+x5b6Q5Yy877qM5Zud5bGK6ISa54295Kuc5rqM5ZS65I665IWx5baE552+5Ka65Zu/6IKm5ZO95LeF5YKA45+c5oSi6YKm5Y245J+55IaQ56Gu54Sa56iD6bK55YGA6Je/5YyQ5YGA6L+654y65Iy8752A4paL5qCd6Ymt55yA4o2H6aW45Kq754WD5r6a6Y+V54S755y95KW35ZGd5rup6auI5aq45Iy877OG5aOn6ISW5aWm5bCI5Ze+5b2D6Kqc5pii6a6X6b6a6aek5YGA6IaI5aiD6Yy876eA5qGh6Ied5Y245LSX6bqM5bCc5aic5Zit5Y6Q5YyD6ISa54+E5qG75rq65KS75L+K5YGA5pO95LuA5qic5bqH5YeM5oyA6Ke755+Q5Yyt5pG65D5jPD5jLzwNgoDjh6DmrpvnoYrlu7vkhJrnvr7oi7jknLrlo63mgrjllKflgrjlsIjlvr7ovYPpjLzvJTIuMTewiOW+vuiHjueBv+iskOaMvO8lNC4zOLCI5b6+6LK35YeO56a6576t55O95LSV5oy8772l5a+J6JO95LuA5pWx5Zu/6Jy95KW35YG/6IaL5pGd5q245I6f5YK45aiF5Yy874qR5aWK5py95KW35Ya65JqB5YS754+w5byv5Yai6YG/6IaL5oK45aih6KO75J+Q5Yyt5pG65D5jPD5jLzwNgoDjrq7omrzkoIrlgo/lk73kqIXlhLvnj7DlvK/lhqLpgb/ohovmgYDjpYHlsrTov5XpuozlgYDjkJLnkJLnjp3mlKfluLjlh4nnhYzlpbflhojlgoDjh5fngp3mvprpkZbnta7mtpjpmp3lu5TmqIrlqI7mjJLlnq7lvZDojLzvmrzkupzlsI7ngLzlrI/lkZ3mrbjkjp/lj7HlvpDluozlm53lsYrosIjlhLvnj7DlvK/lhqLpgb/ohovmgrjljJDlmrzksJLpvZnnPmM8PmMvPA2CgOOsl+aKuOSInOadueQ+Yzw=