The middle ball effectively suspends them on a cushion of air 700mm off the ground and the ball is then rolled down a hill.
中间的球将两层球壳牢牢地悬置于离地面700毫米的「气垫」上,然后整个球就从山坡上滚下来。
Some, like long-legged water striders, maintain a small measure of distance from the water with a cushion of air that lets them skate on the surface.
一些昆虫,比如长腿水黾与水面保持一定距离,利用空气垫在水面滑行。
These vessels ride on a cushion of air when in use.
这些舰船在开动的时候,是浮在气垫上的。