A leopard can't ... its spots.
A leopard can't change its spots.
Bite off more than you can ....
Bite off more than you can chew.
Let ... dogs lie.
Let sleeping dogs lie.
At the ... of a hat.
At the drop of a hat.
... on the bandwagon.
Jump on the bandwagon.
... your tongue.
Bite your tongue.
I ... a rat.
I smell a rat.
It's a ... in the bucket.
It's a drop in the bucket.
Every cloud has a ... lining.
Every cloud has a silver lining.
Take it with a ... of salt.
Take it with a grain of salt.
The ball is in your ....
The ball is in your court.
The best thing since ... bread.
The best thing since sliced bread.
Once in a ... moon.
Once in a blue moon.
Feeling ... the weather.
Feeling under the weather.
Actions ... louder than words.
Actions speak louder than words.
It's a ... of cake.
It's a piece of cake.
... the hook.
Off the hook.
It's the ... of both worlds.
It's the best of both worlds.
... the hatchet.
Bury the hatchet.
Sit on the ....
Sit on the fence.
Let's ... the knot.
Let's tie the knot.
Don't put all your eggs in one ....
Don't put all your eggs in one basket.
Curiosity ... the cat.
Curiosity killed the cat.
I'll be glad to see the ... of him.
I'll be glad to see the back of him.
As ... as a rock.
As solid as a rock.
Cross that ... when you come to it.
Cross that bridge when you come to it.
Close, but no ....
Close, but no cigar.
Kill ... birds with one stone.
Kill two birds with one stone.
You're ... up the wrong tree.
You're barking up the wrong tree.
Burn the ... oil.
Burn the midnight oil.
It's a ... in disguise.
It's a blessing in disguise.
She's a ... horse.
She's a dark horse.