Answer:
I have keys but no locks. I have space but no room. You can enter but canβt go outside. What am I?
I am the book one can never finish reading
What force and strength cannot get through, I with my unique teeth can do. What am I?
There is one in every corner and two in every room.
I am gentle enough to soothe your skin, light enough to fly in the sky, strong enough to crack rocks. What am I?
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.