What's the corresponding idiom to ...?
Fill in the blank
Use the idiom in a sentence.
Explain the meaning
100

"something is quite easy"

It's a piece of cake.

100

________ a leg

break

100

to be/feel under the weather

i.e.: She was feeling a little under the weather because of the break-up.

100

We see eye to eye.

We agree.

200

"it's raining hard"

It's raining cats and dogs.

200

________ corners

cut

200

to have your head in the clouds

i.e.: Guys, sorry, but today I really have my head in the clouds, so I'd better head home, since I clearly won't be of any help.

200

Out of the frying pan and into the fire.

Things are going from bad to worse.

300

"don't be so critical"

cut some slack

300

________ your ________ together

get - act

300

to cost an arm and a leg

i.e.: Son, I'm not buying you that new cellphone, it costs an arm and a leg!

300

Let the cat out of the bag.

Give away a secret.

400

"to argue the opposite, just for the sake of argument"

To play devil's advocate.
400

that's the last ________

straw

400

to bark up the wrong tree

i.e.: You're barking up the wrong tree, officer. I was at home the night of the murder. 

400

He has bigger fish to fry.

He has bigger things to take care of than what we are talking about now.

500

"you're better off not knowing"

Ignorance is a bliss.

500

call it ________ ________

a - day

500

to take a rain check

i.e.: I'll have to take a rain check on that one, my son has just been taken to the hospital.

500

There are other fish in the sea

It's ok to miss this opportunity. Others will arise.