5. How did people first learn about the telephone?

Внимательно читаем текст. В 6 абзаце находим ответ на вопрос.

Bell demonstrated his invention to many people. Over time, more and more telephone lines were installed, and people began to use the invention in their homes and businesses.

Ответ: Bell demonstrated his invention to many people. (Белл продемонстрировал свое изобретение многим людям.)