活塞头部的主要作用是承受气体压力，与（）一起实现气缸的密封并将活塞顶的热量通过活塞环传到气缸壁上。
参考答案：活塞环
下面的句子中各有一处错误，请找出来，并改在右边的横线上。
1. I can't finds my pen. ( )
A B C D
2. What do his father do? ( )
3. He goes to work by foot. ( )
4. I like playing the football. ( )
5. Amy is going to be a actress. ( )
应用可转位硬质合金铣刀片有哪些优点？ 有如下优点：
