若对任意 x＞0， x≤ a( x 2＋3 x＋1)恒成立，则 a的取值范围是（   ）

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SQL Error: select id,body,options from ***_enewstiku_ where sourceid='15529' and id < 2638455 and id<>'2638455' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='15529' and id > 2638455 and id<>'2638455' order by id asc limit 5