gurpreetsingh wrote:
fairy1981 wrote:
The peaks of a mountain range, acting like rocks in a streambed, produce ripples in the air flowing over
them; the resulting flow pattern,with crests and troughs that remain stationary although the air that forms
them is moving rapidly, are known as "standing waves."
(c) with crests and troughs that remain stationary although the air that forms them, is
(d) with stationary crests and troughs although they are formed by rapidly moving air, is
Which one is the better choice?
them; the resulting flow pattern,with crests and troughs that remain stationary although the air that forms
them is moving rapidly, are known as "standing waves."
(c) with crests and troughs that remain stationary although the air that forms them, is
(d) with stationary crests and troughs although they are formed by rapidly moving air, is
Which one is the better choice?
...
