A teacher is teaching a class…

A teacher is teaching a class and she sees that Johnny isn't paying attention, so she asks him, "If there are three ducks sitting on a fence, and you shoot one, how many are left?" Johnny says, "None." The teacher asks, "Why?" Johnny says, "Because the shot scared them all off." The teacher says, "No, two, but I like how you're thinking." Johnny asks the teacher, "If you see three women walking out of an ice cream parlor, one is licking her ice cream, one is sucking her ice cream, and one is biting her ice cream, which one is married?" The teacher says, "The one sucking her ice cream." Johnny says, "No, the one with the wedding ring, but I like how you're thinking!"
Jokes, +1:
At school, Little Johnny's classmate tells him that most adults are hiding at least one dark secret, so it's very easy to blackmail them by saying, "I know the whole truth." Little Johnny decides to go home and try it out.

Johnny's mother greets him at home, and he tells her, "I know the whole truth." His mother quickly hands him $20 and says, "Just don't tell your father." Quite pleased, the boy waits for his father to get home from work, and greets him with, "I know the whole truth." The father promptly hands him $40 and says, "Please don't say a word to your mother."

Very pleased, the boy is on his way to school the next day when he sees the mailman at his front door. The boy greets him by saying, "I know the whole truth." The mailman immediately drops the mail, opens his arms, and says, "Then come give your Daddy a great big hug!"