Lemon.

         
   When I heard the song the Three Lemontree, I know I like lemon. 
   I like lemon's size, not too big, not too small, also it's colour. Light yellow gives me a sense of pure and fresh. However, I most prefer its sour taste. 
   People usually use lemon as a kind of flavor when cooking. They only put one or two pieces of lemon into the drinking water. But I put a whole one. Why? Life is sour, rather than sweet, or bitter.