Answer:
I bring light to a dark world. In a current I travel and through tunnels I am hurled. Touch me and I'll kill you. What am I?
What kind of table can you eat?
Flat as a leaf round as a ring. I have two eyes but can't see a thing.
Taken from a mine and then locked up in a wooden case. I am used by students everyday.
A trail, a union, together tied. Come across me and you will find you cannot change the course I'm on. Without me you cannot travel on. What am I?
It's what light turns into in the night