彼はその問題について論文を書いた。の英語

He wrote a paper on the subject.

He wrote a novel using that as a theme.

He is investigating the problem.

He tried to solve the problem.

He tried solving the problem.

He referred to the subject.

He illustrated the problem with an example.

He is thinking about the problem.

He explained the matter in detail.

He acted on the matter.

He would have his say on the subject.

They are looking into the problem.

He is researching the problem.

He is investigating the problem.

He acted on the matter.

He put too much emphasis on the matter.

He waffled on the issue.

He focused his attention on that problem.

He did not give his opinion on that question.

He dwelt on the subject at great length.

The problem perplexed him.

He put special emphasis on the problem.

He made a thorough analysis of the problem.

The problem perplexed him.

I discussed the matter with him.

He is familiar with the subject.

He tried in vain to solve the problem.

He raised a problem.

He raised a question.

He posed a problem.