One goes choo-choo the other goes chew-chew.
Stick insects!
Because he was grounded!
It was stuck to the chickens foot.
One says, "Spit out your gum!" The other goes, "Choo Choo Choo"
He threw them off their tracks.
He was a good conductor.
A school teacher tells you to spit out your gum, a train says choo choo.
A schoolteacher says "Spit out that toffee" and a train says "Choo choo."