Дополните диалог:
Paul: 1_______. This pipe is very heavy.
Alex: Is it really? What material is it made of?
Paul: 2_______, it is made of metal.
Alex: Why is it made of metal?
Paul: 3_______, because it is a strong material. In any case, it is stronger and more rigid than rubber.
Alex: Is it an expensive material?
Paul: Yes, it is. It is the most expensive material, 4_______.