正确答案: A
Ⅱ+Ⅲ
题目:填料函式密封装置的缺点是()。Ⅰ.密封效果差;Ⅱ.摩擦损失大;Ⅲ.易伤艉轴或铜套;Ⅳ.使用性能差;Ⅴ.寿命短。
查看原题 查看所有试题
学习资料的答案和解析:
[单选题]底脚螺栓与机座和底座的连接方式是()连接。
刚性
[单选题]鸣音发生在螺旋桨桨叶()以外的随边边缘。
0.4R
[单选题]The fuel oil pressure and forced draught pressure should be matched to ensure good combustion with a full steady flameIn the sentence the word “match” means ()
be equal to
[单选题]What function is provided by the crankcase ventilation system on some diesel engines?()
Prevents the accumulation of combustible gases