主轴回转精度误差包括哪些内容?
参考答案:主轴回转精度误差包括主轴径向跳动、轴向跳动和角向摆动三种误差
用所给词的适当形式填空。
1. This dog is very _____(love) and I like it very much.
2. Who does _____(good) in English, John or Mike?
3. I hope to spend two hours _____(play) softball with him.
4. Students can have______ (drive) lessons in American schools .
5. At the_____ (begin) of the trip, most of us felt bored.
6. My mother always cooks _____(taste) meals on Sunday.
7. It rained heavily yesterday, so my father (drive) me to school.
8. The girls finished their work all by_____(them).
9. Yesterday we had a good time _____(chat)with each other.
10. I plan _ ( go ) to Beijing for summer holiday next year .
一艘船向正东方向航行,上午8:50在A处测得一灯塔在北偏东60°方向距离72海里处。上午10:10到达B处,看到灯塔在船的正北方向,求这艘船的航行速度(精确到0.1海里/时)。