This three-legged kettle is from ancient China and is very valuable.

He is looking for a certain book.

Bats use echolocation to fly around in the dark.

A new arbor was built in the park.

The calculation of definite integrals is an important part of calculus.

The Ottoman Empire was once a powerful empire that existed in the Middle East.

Imperialism is a political ideology where some countries dominate others.

I cannot oppose his decision.

Last night, all the lights went out due to a sudden blackout.

He affirmed my proposal.