Sadayoshi is my best friend.

His composition is based on the cantus firmus.

I take the regular bus to school every day.

I live in Baoding city.

His usual location is the seat at the very back of the library.

This contract was established by the stipulation.

He spent a lot of time on the revision of his poetry.

He revised his poetry many times to create a perfect work.

I have been to Dingzhou.

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