Question: what are the 10 examples of idiomatic expression?
Answer: “Hit the hay.” “Sorry, guys, I have to hit the hay now!” ...  “Up in the air” ...  “Stabbed in the back” ...  “Takes two to tango” ...  “Kill two birds with one stone.” ...  “Piece of cake” ...  “Costs an arm and a leg” ...  “Break a leg”