He is known as a pioneer in that field.

We need test subjects to confirm the effects of this new drug.

He is working hard for the people as a true statesperson.

I purchased this product from a trustworthy seller.

He is recognized as an outstanding person in that field.

The complainant made his misconduct public.

He is a hard-working laborer.

The preacher started preaching in the church.

He is considered a rebel against the government.

He is known as an excellent educator.