This experimental device is used to create new substances.

I do laundry using synthetic detergent.

A composite number, unlike a prime number, is represented by the product of two or more natural numbers.

This new compound word is popular among young people.

The government declared a state of emergency to prevent the spread of the new coronavirus.

The central processing unit of this computer is very fast.

My younger sister became a first-year senior high school student this year.

My younger brother is currently in his third year of high school, preparing for university entrance exams.

My younger sister is in her second year of senior high school, and she is busy studying every day.

Mr. Takaharu is my best friend.