Question

Which is an example of an idiom?
Today we will receive three inches of rain
The rain today is fierce and punishing
It is raining cats and dogs
She hoped the rain would wash away her sorrows

Answer 1

An example of an idiom from your choices is "It is raining cats and dogs." This phrase is an idiomatic expression that means it is raining very heavily, and it doesn't literally mean that cats and dogs are falling from the sky.