Knock, knock.
Who's there?
Lettuce!
Lettuce who?
Lettuce in, it's cold out here!
From the first knock-knock joke to the last,?Lettuce In!?provides the perfect introduction for young joke tellers.?With whimsical animal characters and easy-to-follow jokes, this book also?features a flap on every spread. The flaps reveal the surprise punch-line to each hilarious knock-knock joke!