Why shouldn't you tell jokes to an egg?

Because it may crack up!

Teacher: "Class, we'll have only half a day of school today morning."

Students: "Yaaayyy!"

Teacher: "We'll have the other half this afternoon."

A man enters the kitchen, opens the sugar box, looks inside and closes it.

He does it again and again. Why?

Because the doctor told him to check his sugar levels regularly.

Tennis Coach: "I know everything about tennis. You can ask me anything."

Student: "Sir, how many holes are there in the net?"