He is learning Taiwanese using Zhuyin fuhao.

I have been to Ho Chi Minh.

I have been to Blagoveshchensk.

He explored the deep sea with a bathyscaphe.

He keeps the words 'Don't hesitate to correct your mistakes when you make them' in his heart, always striving for self-improvement.

I bought a new costume for Halloween.

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.