在R上定义运算?： x? y＝ x(1－ y)．若不等式( x－ a)?( x＋ a)＜1对任意实数 x都成立，则(  )

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SQL Error: select id,body,options from ***_enewstiku_ where sourceid='15530' and id < 2638578 and id<>'2638578' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='15530' and id > 2638578 and id<>'2638578' order by id asc limit 5