下列哪一项不是车削加工的特点()
A.刀具简单
B.易于保证零件各加工表面间的相互位置精度
C.适用于有色金属材料的精加工
D.切削不连续,切削过程不平稳
参考答案:D
哎呀,有个外星人来到地球了!他长得好奇怪!请根据他对自己的描述,画出他的样子吧!
Hello, friends! I am an alien (外星人). Look at me. I have a big (大的) head. I have a round (圆的) face.
On my face, there are three eyes. Two are big, the other one (另一个) is small (小的). I have a long (长的)
nose. I have a small mouth. I have five ears. I have two hands. I have a tail (尾巴). Don't be afraid of (害怕)
me. I am your friend.
铁制品锈蚀的过程,实际上是铁与空气中的______和______ 等发生化学反应的过程.据有关资料报导,世界上每年因腐蚀而报废的金属设备或材料相当于年产量的20%~40%.保护金属资源,人人有责.请写出一条防止铁制品生锈的方法______.