I'm an object; good at drawing. I draws without using any drawing instrument, yet I can draw even better and faster than the world's best artist. But what I will draw won't stay permanent and what I draws may see me or not. What am I?
A mirror. Humans can see it but objects cannot.
Cái gì mà đi thì nằm, đứng cũng nằm, nhưng nằm lại đứng?