What is the main verb of this sentence?

My pocket book collection can be read anytime during travel.

He gifted me a signed copy of his new book.

We don't need to reinvent the wheel.

This secondary burial grave is believed to have been used by ancient people to honor the dead.

He defeated the enemy using a two-sword style.

His painting expresses pure beauty.

Our company's headquarters is in Tokyo.

The digital song catalog for karaoke has been updated.

At the end of the meeting, we concluded with a ceremonial hand clapping of three claps.