紧固螺丝时,防止螺杆受力过大,必须按规定的()扭紧。 ["力","功","功率","扭矩"]
PP—R管道电熔连接过程需要注意()。 ["清洁","找正","通电加热时间","冷却时间"]
耙装机滚筒上的余绳不得少于()圈。 ["A、2","B、3","C、5"]
PP—R管道电熔连接分为()。 ["电熔承插连接","电熔回形连接","电熔对接连接","电熔鞍形连接"]
电液转辙机在解锁和锁闭过程中,动作杆上的负载在推板上只占(). ["二分之一","三分之一","三分之二","四分之一"]
继叙咏(sequence)