SF6电压互感器吸附剂更换时,对户内设备,应先开启强排通风装置()min后,方可进入,工作过程中应当保持通风装置运转。
A.15
B.20
C.30
D.60
参考答案:A
扣件式钢管脚手架施工,搭设遇门洞时,脚手架可挑空1~5根立柱,悬空的立柱用斜杆逐根连接,单排架可增设立柱或吊设一短杆将荷载传至两侧横向水平杆上。
Is this the young engineer ________ you want to have ________ the computer for me?
A.who, repaired
B.that, repairing
C.who, to repair
D.that, repair