Because he has a hearing impairment, he often communicates by writing.

Because she has a hearing impairment, she often communicates by writing on paper.

He broke the glass carelessly.

His carelessness caused the accident.

He is contributing to the community as an unpaid doctor.

He is working at the hospital as a resident.

This issue requires attention.

Please prepare the necessary documents before starting the refund process.

Do you understand the necessity of this project?

That information is unnecessary.