某药的降解反应为一级反应，其反应速度常 数k=0.001h'则其有效期为（  ）。

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SQL Error: select id,body,options from ***_enewstiku where sourceid='24961' and id < 2127106 and id<>'2127106' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku where sourceid='24961' and id > 2127106 and id<>'2127106' order by id asc limit 5