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.

Almond oil is indispensable in my skincare routine.

This medicine contains bitter almond oil dissolved in water, and it tastes bitter.

The National Research and Development Agency plays a crucial role in advancing science and technology.

He decided to change his character.

He said he would come back tomorrow.

I solved this problem over and over again, and finally understood all the patterns thoroughly.