图1-21所示电路中电压Uab的值为（ ）。 

试卷相关题目

SQL Error: select id,body,options from ***_enewstiku where sourceid='30079' and id < 2435295 and id<>'2435295' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku where sourceid='30079' and id > 2435295 and id<>'2435295' order by id asc limit 5