SL7-130水龙头提环销夏季的润滑材料为()。
A.黄油
B.钙基润滑脂
C.机油
D.柴油
参考答案:B
I knew that________ would ever discourage him;he would never give up wanting to be a director.[ ]
A.something
B.anything
C.everything
D.nothing
铲斗前壁材质为()。
A.高锰钢
B.合金钢
C.16锰
D.铝合金