1£®“¹«²îΪ0µÄµÈ²îÊýÁÐÊǵȱÈÊýÁД£»“¹«±ÈΪ µÄµÈ±ÈÊýÁÐÒ»¶¨ÊǵݼõÊýÁД£»“a,b,cÈýÊý³ÉµÈ±ÈÊýÁеijäÒªÌõ¼þÊÇb²=ac”£»“a,b,cÈýÊý³ÉµÈ²îÊýÁеijäÒªÌõ¼þÊÇ2b=a+c”£¬ÒÔÉÏËĸöÃüÌâÖУ¬ÕýÈ·µÄÓР                               £¨    £©

       A£®1¸ö                    B£®2¸ö                    C£®3¸ö                    D£®4¸ö

2£®ÒÑÖªÊýÁÐ{a_n}ÖУ¬a_n= £¨n∈N£©£¬ÔòÊýÁÐ{ a_n}µÄ×î´óÏîÊÇ                                 £¨    £©

       A£®µÚ12Ïî                                                    B£®µÚ13Ïî                

       C£®µÚ12Ïî»ò13Ïî                                      D£®²»´æÔÚ

3£®ÔڵȲîÊýÁÐÖУ¬Ç°nÏîµÄºÍΪS_n,ÈôS_m=2n,S_n=2m,£¨m¡¢n∈NÇÒm≠n£©£¬Ôò¹«²îdµÄֵΪ£¨    £©