Don’t start problems or cause trouble
Work until late at night
Happens very rarely; uncommon
Let sleeping dogs lie
Let the cat out of the bag
Burn the midnight oil
It’s not rocket science
Wait and be patient
Can’t stay calm (relax) because you’re nervous
Good idea or invention
Ants in one’s pants
Cost an arm and a leg
Once in a blue moon
Hold your horses
Very expensive
Tell a secret
Best thing since sliced bread
It’s not hard.
