On completion of cleaning, all surfaces are to be free of visible dirt, bacterial and residue cleaner leaving a clean appearance.

在清洁完成后，一切外表都确保整洁，不应有明显的灰尘、细菌和清洁剂残留物出现。

youdao

He throws a handful of dirt on the bridge and that makes it visible.

他丢了一把垃圾在桥上，而且使它容易看得见。

youdao

Steel surface should be no visible oil, dirt, scale, rust and paint coating and other debris should as far as possible eliminate, any attachments should be strong.

钢材表面应无可见油脂、污垢、氧化皮、铁锈和油漆涂层及其它杂物应尽可能除去，任何附着物均应是牢靠的。

youdao

Confused, she looked around for a culprit and then realized that she was caked in dirt, her clothes were torn, and she had visible gashes.

FORBES: Entrepreneurs

Visible below, in the valley, was a running track, a soccer pitch, and a giant dirt lot, where you could hear the shouts and screams of children at play.

NEWYORKER: Master of Play