Answer:
I have a head tail but no arms and legs.
You may enter, but you may not come in. I have space, but no room, I have keys, but open no lock. What am I?
When I live I cry if you don't kill me I'll die.
When I get closer my tail grows longer but when I go away my tail leads the way.
I am easy to waste. I am unstoppable. What am I?
Strip the skin under my skin, and my flesh you'll reveal. It tastes sweet and tart, now throw out the peel. What is it?