对于一阶电路的时间常数，表达式正确的有（   ）。

试卷相关题目

SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69473' and id < 4501250 and id<>'4501250' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69473' and id > 4501250 and id<>'4501250' order by id asc limit 5