层流中流体在进入管道的弯曲部分时，流速 的变化为（     ）

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SQL Error: select id,body,options from ***_enewstiku where sourceid='25738' and id < 2163364 and id<>'2163364' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku where sourceid='25738' and id > 2163364 and id<>'2163364' order by id asc limit 5