The Tertiary period was a very important time in the history of the Earth.

He passed the medical school entrance exam on his first try.

He passed the difficult exam.

The crescent moon is floating in the sky, it's very beautiful.

My younger sister is twenty-two years old.

It is thirty-three kilometers to my house.

I have been studying Japanese for four months.

The beauty of the four seasons symbolizes the charm of nature in Japan.

This building has a four-step staircase.

Kenji is my best friend.