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