The product was defective, so I asked the clerk to return the money.

She described the pain of a broken heart as tears.

I don't know a thing about him.

He emphasized his belief by saying, 'I believe in order to understand.'

This shape is a parallelogram.

He is an excellent arranger, and has produced many musical works.

The calculus of variations is a branch of mathematics that deals with the optimization of functions.

He is good at playing Beethoven's variations.

The amygdala is a part of the brain that controls our emotions.

Almond oil is indispensable in my skincare routine.