正确答案: D
Ⅱ+Ⅳ+Ⅴ
题目:柴油机的重要螺栓的材料常选用优质碳钢和优质合金钢,如()。Ⅰ.15钢;Ⅱ.45钢;Ⅲ.20Cr;Ⅳ.40Cr;Ⅴ.35CrMo。
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[单选题]今测得某船主机曲轴臂距值,求在垂直平面上的臂距差Δ⊥=()。
L上-L下
[单选题]直尺-塞尺法应用较多,且方法方便、简单、灵活,但()。
测量精度低
[单选题]水润滑艉轴承首端设置填料函式密封装置是为了()。
防止海水流入机舱
[单选题]In a complete oil/water separator, more oil will separate out onto the underside of these plates and travel outwards until it is free to rise into the oil collecting space Whats the meaning of "it" in the sentence above?()
oil