Answer:
I am heavy forward, but backward I'm not. What am I?
I look like a tiny trombone
I am one small little piece of paper yet sometimes hold lots of value. I am all you need to get in to big events but will cost you. I am an important part of travel. And if lost you're not coming.
I have feathers that help me fly; with head and body but I'm not alive. Very skinny and a fixed length how far I go depends on your strength.
What invention lets you look right through a wall?
It flows out of the soil, It burns you if it boils, And holds us in its coils, More valuable than gold, As black as it is old.