The new airport has opened.

This problem is very difficult.

The difficulty of this problem makes me scratch my head.

This problem is so difficult to solve, it gives me a headache.

We are engaged in trade between Japan and China.

The chance encounter with him changed my life.

He met a beautiful woman by chance in the park.

We bought fresh fish at the seaport.

The operculum of this shell is very beautiful.

The new school is scheduled to open next year.