She is as busy as a bee.
She is extremely active, productive, and hard-working like bees.
The classroom was a jungle.
The classroom was very loud and full of activity, like jungles.
He was a lion in the fight.
He showed extreme courage, strength, bravery, and fierceness, like a lion.
The car was as loud as a thunderstorm.
The car's engine was very loud.
Her voice was music to his ears.
He was so happy to hear her voice, just like he is happy to hear music.
The pizza was as hot as lava.
The pizza was extremely hot.
I tried to break the ice with a new group of students in class today.
I tried to start a conversation in a social situation.
I need to hit the books because I have a biology test tomorrow.
I needed to study seriously.
The math homework was a piece of cake for her.
He stayed home from school because he felt under the weather.
He stayed home because he was sick.
We only get homework once in a blue moon.
We only get homework once in a while.
She had to burn the midnight oil to finish her essay.
She had to stay up late to finish her essay.
He accidentally spilled the beans about the surprise party.
He accidentally revealed the secret.
Those concert tickets cost an arm and a leg.
He was in hot water for not turning in his assignment.
He was in trouble for not turning in his work.