a) As cool as a cucumber. (to be very calm and relaxed, especially in a difficult situation)
He remains cool as a cucumber in all circumstances.

b) Have your cake and eat too. (have the advantages without the disadvantages)
Government job is not an easy task, you cannot have your cake and eat it too.

c) In a Pickle. (in some trouble or a mess)
She find herself in a pickle when she failed to reply her student's query in the classroom.

d) Take a cake. (Be the most outstanding in some respect, either the best or the worst.)
That advertising slogan really took the cake.

e) Sell like hot cakes. (selling very well)
His book has got much popularity because shopkeepers sold it like hot cakes.

f) As flat as a Pancake.
This table is as flat as a pancake that is why I want to buy it for my kitchen.

g) Take something with a grain of salt. (to consider something to be not completely true or right)
I've read the article, which I take with a grain of salt.

h) Like two peas in a pod. (very similar)
My resemblance to my sister is very much; we are like two peas in a pod.

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The Me you have always known, the Me that's a stranger still.