Complete the sentences with suitable parts of the idioms.

Write one word in each gap.

Julia is a straight-A student. This exam will be a [ ] of cake for her.

A fantastic firework display at the end of the festival was the real [ ] on the cake!

Those T-shirts sell [ ] hot cakes. We have to hurry if we want to buy one.

You can both help us and have a good time at the park if you agree to walk our dog. Don't miss your chance to [ ] your cake and eat it.