instrument rolling bearing

例句：

1. 1. The scientistuses a microscope to observe the microscopic world.
   这位科学家使用显微镜来观察微观世界。
2. 2. The engineer designed a new machine for the factory.
   这位工程师为工厂设计了一台新机器。
3. 3. The teacher used a ruler to measure the length of the paper.
   老师用直尺测量纸张的长度。