Invasive species can have a major impact on the natural environment.

He is always hanging out with bad friends. Truly, birds of a feather flock together.

He is good at playing the guqin.

I am learning Old English.

This antique clock is a keepsake from my grandfather.

This old document is very important for understanding our history.

Archaebacteria are one of the oldest life forms on Earth.

Mr. Furukyo is my best friend.

Pangu, who appears in Chinese mythology, is said to have created the universe.

He has come to look old recently.