层流的速度分布剖面形状是（     ）

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SQL Error: select id,body,options from ***_enewstiku where sourceid='25739' and id < 2163408 and id<>'2163408' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku where sourceid='25739' and id > 2163408 and id<>'2163408' order by id asc limit 5