下列哪种塑料均属于热固性塑料() ["聚乙烯和聚氯乙烯","聚氯乙烯和酚醛树脂","聚乙烯和环氧树脂","酚醛树脂和环氧树脂"]
汽车给环境带来的污染主要包括排气污染、噪声污染、汽车废弃物污染和扬尘。
自动变速箱保护剂的养护作用不含以下哪一点()。 ["清除油泥胶质","预防早期磨损","减少摩擦","防尘防水"]
渗碳用钢通常采用()钢。 ["35CrMnSiA","5CrNiMo","20CrMo","38CrMoAlA"]
汽油机的五大系统是指() ["A、曲柄连杆机构","B、冷却系","C、点火系","D、配气机构","E、起动系","F、润滑系"]
气相色谱分析对检测器有何要求?