Best easy riddles

What goes up but never comes down?

I eat other animals. I have a big mouth. I am green. I live in the water. Who am I?

What is the difference between yesterday and tomorrow?

I create my lair with earthen string and dispatch my prey with a biting sting. What am I?

Why was Karl Marx buried at Highgate Cemetery in London?

There are a number of books on a shelf. If one book is the 6th from the left and 4th from the right, how many books are on the shelf?

A boy was rushed to the hospital emergency room. The ER doctor saw the boy and said, "I cannot operate on this boy. He is my son." But the doctor was not the boy's father. How could that be?

What did the baseball glove say to the baseball?

What does the Invisible Man drink at snack time?

A magician was boasting one day at how long he could hold his breath under water. His record was 6 minutes. A kid that was listening said, "that's nothing, I can stay under water for 10 minutes using no types of equipment or air pockets!" The magician told the kid if he could do that, he'd give him $10,000. The kid did it and won the money. How did he do it?