单级冲击电压发生器中，为获得1.2/50 μs标准雷电波，靠调节（ ）实现波前与波尾时间。（0.5）

试卷相关题目

SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69423' and id < 4495241 and id<>'4495241' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69423' and id > 4495241 and id<>'4495241' order by id asc limit 5