Ответ:
1.This shopping centre was built last year.
2.The car was being washed by dad all morning.
3. The test has been already written (by us).
4. A new laptop will be bought next week (by us).
5. A lot of new houses had been already built by the company by the time I came back to my hometown.
6. The cleaning will have been finished (by me) by the time the guests come.
Объяснение:
То, что в скобках - это можно писать или нет, по собственному усмотрению, на смысл это не влияет.