All these funny, punny knock-knocks have a twist: they play games with names to create big belly laughs for kids.  Some are just out of this world: Knock-knock. Who’s there? Martins. Martins who?  Martins from outer space. Others stretch out the fun in a series of jokes: Knock-knock. Who’s there? Boyce. Boyce who? Boyce will be Boyce. Knock-knock. Who’s there? Gail. Gail who? And Gails will be Gails. What irresistible amusement for young comedians!