Hold your gerbil while sitting down or over a surface.
The kind of water feature where water trickles smoothly over a surface is better.
Rolling friction occurs when a wheel, ball, or cylinder rolls freely over a surface, as in ball and roller bearings.
In January 2009, fossil hunters concentrated their search over a surface about 300 yards from where Lucy's baby was found.
When poured over a surface, the virus self-assembles into a layer of nano-tendrils, each pointing upward like a blade of grass.
The contours of the figures seem to dissolve into the background, and the light seems to flow gently over a surface.
In 2011 they created a "nanocar," which consisted of a "chassis" and four molecular motors for wheels and which could drive over a surface.
They do so across the expanse of the museum's fourth floor, tracing their loops over a surface painted with a blueprint for the building.
This can happen either because the vehicle strikes a car, curb, guard rail or other low object, or because one side of the vehicle starts traveling over a surface that slows it down, like a muddy shoulder of the road.
The basic inspection technique for checked baggage will be the same as for carry-on bags: a technician will rub a muslin swab over a surface, then feed the swab into a trace detector.
The technique of laying paper over a surface and lifting an impression with a crayon or pencil is traditionally used to collect names from tombstones and images from memorial brasses.
