采样保持（S/H）电路的作用，下列说法正确的是（ ）。

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SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69493' and id < 4501569 and id<>'4501569' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69493' and id > 4501569 and id<>'4501569' order by id asc limit 5