The Khmer Rouge caused the darkest period in Cambodian history.

This room is so dark that I can't see anything.

This is the most beautiful flower.

His irresponsible behavior caused an accident.

I plan to travel to Cambodia next year.

What is the best time to travel?

She applied her new lipstick.

Please put the book on the shelf above.

In addition, he can play the piano.

He is interested in history.