Answer:
I'm an animal. I love marching. I always wear a tuxedo. What am I?
I save lives on the ground and in the air. What am I?
Sometimes I am white, sometimes I am dark. Most people love me. What am I?
I am a portal to another world which you cannot enter. Only you can see me but I can't see you.
I am always in front of you but you will never see me
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.