So, they developed this bifurcated tool, which would be appl--you'd put the stuff on the surface of the tool and then you'd scratch the skin in a certain way so that you could produce sort of a reproducible introduction of the vaccine into the skin.

所以他们发明了一种分为两叉的工具,把疫苗抹在这种工具表面上,然后以某种方式在皮肤上刮,这样就能将疫苗,重复不断地引入到皮下

耶鲁公开课 - 生物医学工程探索课程节选

But the hugely controversial reorganisation in North Wales didn't even scratch the surface of these changes for their area.

BBC: "Very significant heat in the system"

But, Shannon insisted during that hike, just documenting the malaise in an eight-hundred-word editorial piece couldn't even scratch the surface.

FORBES: What To Do When You Can Do Anything?

And, though much has been done to digitize content, it is impossible to scratch the surface, especially on the budget afforded to libraries today and in times past.

FORBES: Will Public Libraries Become Extinct?