Английский. Use the active form (Simple, Continuous or Perfect) of the verbs in the brackets.

1. Clear windows have been used since the invention of glass to cover small
openings in a building.
2. Manufacturers produce different types of glass
nowadays.
3. The majority of your portfolio consists of pictures of work that
you have completed.
4. You get up to a 50% discount on the materials you use
when you purchase them directly from suppliers.
5. затерян
6. After collecting this
information, the designer went to the shop and bought all necessary materials.
7. They have been working out a new production plan for two weeks.
8. They were conducting an
experiment on the construction site from 9 till 12 yesterday.
9. City houses have
become much more comfortable now.
10. They will need the help of many other
skilled designers tomorrow.
11. He has known the chief designer for three years.
12. The designer was using a computer in the office at 3 o’clock yesterday.
13. They had sent a project to a project manager before I found the mistake.
14. They have been developing this product for two years.
15. Recent decades have seen the rise of specializations within the profession of a designer.
16. They are painting the exterior of the house now.
17. Charlie has seen the client three times this week.
18. Megan will not attend the meeting tomorrow.
19. They were discussing a new fashion collection when I arrived.