Answer:
I am a protector. I sit on a bridge. One person can see right through me while others wonder what I hide.
I march before armies a thousand salute me. My fall can bring victory but no one would shoot me. The wind is my lover one-legged am I. Name me and see me at home in the sky.
I can be sweet or sour. I do not rhyme with any other word
One simple click, one simple flash. A piece of memory, for years I'll last. What am I?
Without a bridle, or a saddle, across a thing I ride a-straddle. And those I ride, by help of me, though almost blind, are made to see. What am I?
Almost everyone needs it, asks for it, gives it. But almost nobody takes it.