Answer:
I am useless when together but useful when I am broken apart. What am I?
I widen my jaws when you poke two fingers in me. I especially like to devour papers
I make everyone blind. You can't see me but I will always come back for you. What am I?
I am the black child of a white father a wingless bird flying even to the clouds of heaven. I give birth to tears of mourning in pupils that meet me even though there is no cause for grief and at once on my birth I am dissolved into air.
I am a sound made by felines when petted.
Give it food and it will live, give it water and it will die.