27习题又补了点重要细节（1 / 2）

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55S35Lq655qE6aOO5qC844CCDTwvcD48cD7ouqvmnZDigKbigKbkuZ/mr5TpgqPmmZrnnIvliLDnmoTmm7TmjLrmi5TjgIHmm7Tlo67noZXjgIINPC9wPjxwPuS7luS7iuWkqeS7jeaXp+aYr+a3seeBsOiJsuilv+acje+8jOWGhemHjOaNouS6humrmOmihue+iue7kuihq+OAguS4jeeul+i0tOi6q++8jOS9huiDuOiCjOeahOi9ruW7k+S7jeaXp+iLpemakOiLpeeOsOOAguiCqeiDjOWuvemYlO+8jOaPkuWcqOWFnOmHjOeahOmCo+WPquaJi+iHgu+8jOmalOedgOW4g+aWmeS5n+iDveeci+WHuuiHguiCjOeahOeXlei/ueOAgg08L3A+PHA+5LiO54i454i455qE5by65aOu5LiN5ZCM77yM5LuW5piv5Y+m5LiA56eN5pu04oCm4oCm6K6y56m255qE5L2T5oCB44CC5qKB6Z2S57695pqX5pqX5a+55q+U77yM5oOz6LW36Ieq5bex5pyA6L+R5bi45Yi35Yiw55qE4oCc6KGj5p625a2Q6Lqr5p2Q4oCd77yM6KeJ5b6X5pa55LuO5a6J5aSn5qaC5bCx5piv6YKj56eN44CCDTwvcD48cD7kuIDmnaXkuozljrvvvIzmnaXlm57miZPph4/jgILmooHpnZLnvr3nnIvlvpfmnInngrnlpKrkuYXkuobjgILkuYXliLDkuI3og73nlKjkuI3nu4/mhI/lvZPlgJ/lj6PvvIzkuYXliLDkuIDlkJHnpLzosozlvpfkvZPnmoTmlrnku47lronpg73kuI3og73lgYfoo4XnnIvkuI3liLDvvIzlj6rog73nnqfov4fmnaXjgIINPC9wPjxwPuS4peagvOadpeivtO+8jOi/meaYr+esrOS6jOasoeWvueinhuOAgg08L3A+PHA+5LiN5q+U5LiK5LiA5qyh546v5aKD5qih57OK77yM6L+Z5qyh5qKB6Z2S57695riF5pmw55yL5Yiw5LuW55qE55y856We4oCU4oCU5b6I5YeM5Y6J55qE77yM5LiA5Lqb5Lqb55aR5oOR77yM5LiA54K554K55o6i56m277yM5Y205Lu/5L2b6KaB56m/6YCP5aW555qE6Lqr5L2T77yM55yL5ZCR5b6I5rex5aSE44CCDTwvcD48cD7lsJHlpbPlv4PkuK3mnKzlsLHmnInprLzvvIzkuIDnm7TlronmhbDoh6rlt7HlkozmooHlj5nnmoTkurLlr4blnKjniLblpbPnlYzpmZDkuYvlhoXvvIzlj6/niLjniLjouqvovrnnmoTmnIvlj4vjgIHkvJnkvLTpg73mmK/kurrnsr7vvIzpmr7pgZPkvJrnnIvkuI3lh7rvvJ8NPC9wPjxwPuWlueS7peWJjeS7juS4jeinieW+l++8jOi/meS4gOWIu+WNtOW/veeEtuW/g+iZmui1t+adpeOAgg08L3A+PHA+5qKB6Z2S57696KOF5L2c6Iul5peg5YW25LqL5Zyw5pS25Zue6KeG57q/77yM5a6e5YiZ5b+D5Y+j5bey57uP5Zyo5oCm5oCm5Lmx6Lez44CC5LiN55Sx5pqX6Ieq5oCo5oC86YKj5Lqb6KeG6aKR77yM6YO95oCq5a6D5Lus77yM6K6p5aW5546w5Zyo5oC75b+N5LiN5L2P5Y675rOo5oSP55S35Lq655qE6Lqr5L2T44CCDTwvcD48cD7mooHlj5nlr5/op4nliLDlpbPlhL/ouqvkvZPnqoHnhLbnmoTlg7XnoazvvIzlhbPliIflnLDnnIvov4fljrvvvJrigJzmgI7kuYjkuobvvJ/igJ0NPC9wPjxwPumdkue+veaRh+aRh+WktO+8jOS7sOi1t+iEuO+8jOabtOe0p+WcsOaPveS9j+S7lueahOaJi+iHgu+8jOWHoOS5juaVtOS4qui6q+S9k+mDvemdoOS6huS4iuWOu++8muKAnOaIkeacieeCueWEv+aDs+WbnuWutuS6hu+8jOaZmumlreWwseS4jeWHuuWOu+S6huWQp++8n+KAnQ08L3A+