He works at the Ministry of Health, Labour and Welfare.

He is a very quiet person.

There are a few problems.

Special relativity is one of the fundamental theories of physics.

This software has forward compatibility.

This software maintains backward compatibility.

He lowered his head and greeted.

We decided to hold a meeting to determine the solution to this problem.

He worked hard without giving up.

Please teach me how to calculate the area of this circular sector.