Answer:
I am the best thing that can happen after a stick hits a ball.
I am a portal to another world which you cannot enter. Only you can see me but I can't see you.
What goes up and down stairs without moving?
I am a seven letter word. I am very heavy. Take away two letters from me and you will get eight. Take away one letter from me and you will get 80. What word am I?
I love spinach.
Though not a plant, has leaves. Though not a beast, has spine. Though many wouldn't need this thing, It's more valuable than wine.