求图示电路中的电压U=（）V。 

试卷相关题目

SQL Error: select id,body,options from ***_enewstiku where sourceid='32670' and id < 2598644 and id<>'2598644' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku where sourceid='32670' and id > 2598644 and id<>'2598644' order by id asc limit 5