The phone rang in the middle of the night.

Polytetrafluoroethylene is a very slippery material.

He said, 'It's difficult to make a life,' explaining the phrase 'When a man steps over the threshold, he has seven enemies.'

The Mesolithic is the era between the Paleolithic and the Neolithic.

He started a business without a plan, forgetting the lesson of 'peach and chestnut seeds take three years to bear fruit, persimmons eight years.'

A terrestrial planet may have an environment similar to Earth.

The puborectalis muscle plays a crucial role in controlling defecation.

This speech synthesizer generates very high-quality voices.

I think we should try a different method.

I'm in the middle of a conversation, so please wait a moment.