Перевод

В каких предложениях глагол to be выражает модальность? Переведите только эти предложения на русский язык.

1. Plastics are now produced on a wide scale. 2. The reconstruction of non-ferrous metal processing plant was to be completed by the end of the year. 3. They are discussing a new production plan now. 4. The sun is a potential source of energy. 5. All the work is to be done by automatic machines.