These idioms are useful for the speaking part of an exam

Top 10 idioms for Cambridge exams

without delaying or wasting any time:

I made this decision without further ado.
Without further ado, let's get down to business.

to immediately start dealing with the most important part of something:

I didn't have long to talk so I cut to the chase and asked whether he was still married.
OK, stop rambling, just cut to the chase.

not able to decide something:

Many consumers are still on the fence, waiting for a less expensive computer to come along.

to start dealing with an unpleasant or dangerous situation because you cannot avoid it any longer:

I hate going to the dentist, but I'll just have to bite the bullet.

the last problem in a series of problems that finally makes you give up, get angry etc.:

Making me work late on a Friday was the last straw and I quit!

to be satisfied with what you have done, so that you do not make any further effort:

In such a competitive market, the leading company can't afford to rest on its laurels.

a subject or problem that no one wants to deal with, because it is difficult and any decision might make people angry:

The issue has become a political hot potato.

an important subject or problem that everyone knows about but no one mentions:

The race issue is the elephant in the room in this election.

used when you are stating the main facts about something in a short clear way:

Okay, that’s our proposal in a nutshell. Any questions?
In a nutshell, everything went well.

to be unable to understand a situation clearly because you are too involved in it:

The information presented in this textbook is so disorganized that I can't see the wood for the trees.

can't see the wood for the trees (BrE)
can't see the forest for the trees (AmE)