Electrical Appliance

Little Johnny is at school, and at the end of the day the teacher asked the students to bring one electrical appliance for "Show & Tell" the next day.

So the next day every kid has something. The teacher asks Wendy, "What did you bring?"
Wendy said, "I brought a Walkman."
The Teacher said, "And what is it for?"
Wendy said, "You can listen to music with it!"

The teacher said, "That is nice Wendy, and what did you bring Kenny?"
Kenny said, "I brought an electrical can opener, it opens cans, miss!"
The Teacher said, "Well done, Kenny, but I see that Johnny didn't bring anything!"

Little Johnny said, "Yes, I did. It's in the hall."
The whole class looks out into the hall.

His Teacher said, "WHAT IS THAT, JOHNNY?"
Little Johnny said, "It is a heart/lung device. They use it in hospitals to keep your heart going!"

Teacher said, "And what did your father say about it?"
Little Johnny answers back, "AAAAAAAHHHHHHHHHHHHHH!!!"