Polonium is one of the radioactive elements.

Einstein proposed the theory of relativity.

He looked back.

This road is very crowded.

This route leads to the library.

It's difficult to understand the movement of the great stag in shogi.

I have been studying Japanese for six months.

I plan to travel to Europe next year.

He is interested in the design of rocket engines.

She had a new locket around her neck.