I want to go to Iturup.

He tried to imitate the crowing of a rooster.

I bought a new top.

An albatross is a bird with long wings.

Tetracosane is one of the important compounds in organic chemistry.

This compound is called triacontane and is often used in organic chemistry.

He flatly refused my proposal.

He is really a forgetful person, always forgetting names.

Tryptophan is one of the essential amino acids that cannot be produced in the human body.

His sharp wit helped to solve the problem.