Употребите глагол в активном или пассивном залоге
The American physicist. Mr.Hall (make) an important discovery when he was still a student. The effect which (name) after him (include) soon in all textbooks on physics. Once, many years later. Mr.Hall (invite) to a congress of physicists. Many participants of the congress to whom Mr.Hall (introduce) asked one and the same question. "Arent you any relation to the old Hall?" He usually (say).