clean surface

例句：

1. 1. The engineer cleaned the surface of the machine before it was used again.
   工程师在机器再次使用前清洁了其表面。
2. 2.After the surgery, the patient's clean surface is ready for dressing.
   手术后，患者的清洁表面准备好进行包扎。
3. 3.The team worked hard to clean the surface of the factory floor before the new machines were installed.
   团队努力工作，在安装新机器之前清理了工厂地板的表面。