Best riddles

I am not alive but I grow. I don't have lungs but I need air. What am I?

Six glasses are in a row. The first three are filled with milk and the last three are empty. By moving only one glass, can you arrange them so that the full and the empty glasses alternate?

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. What am I?

A girl was ten on her last birthday, and will be twelve on her next birthday. How is this possible?

A teacher decides to give a pop quiz one day but all of her students refuse to take the quiz thinking that the teacher will call off the quiz. She can give only one of these students a detention for skipping the quiz. All of the students know each other's names and if a student knows he/she is getting a detention they take the quiz. How can she threaten her students with the single detention so they all take the quiz?

I am always hungry and will die if not fed, whatever I touch will soon turn red.

I move very slowly at an imperceptible rate, although I take my time, I am never late. I accompany life, and survive past demise, I am viewed with esteem in many women's eyes. What am I?

I'm a fruit. If you take away my first letter, I'm a crime. If you take away my first two letters, I'm an animal. If you take away my first and last letters, I'm a form of music. What I am I?

Where can you find rivers with no water, cities with no buildings and forests with no trees?

I have a bed but I do not sleep. I have a mouth but I don't eat. You hear me whisper, but I never talk. You can see me run, yet I never walk. What am I?