I think his Japanese has improved quite a bit, hasn't it?

He is a master of the piano.

Who is the person in charge of the project?

His handwriting is very unique, and can be recognized immediately.

She works as a stripper.

I am responsible for the contents of this document.

We need to analyze this data.

I am solving integration problems in math class.

Analytical chemistry is a science for clarifying the components and structure of substances.

We conducted a meta-analysis on this issue.