1.This house was built 100 years ago. (Change into active voice)
$\rightarrow $ People ...
2.A friend of mine helped me to get a job. His father is a manager of a company.
(Combine the sentences, using Relative clause)
$\rightarrow $ A friend of mine ...
3.John Bridge is one of my oldest friends. He has just gone to live in Canada.
(Combine the sentences, using Relative clause)
$\rightarrow $ John Bridge ...
4.Sometimes life is very unpleasant for people who live near the airport.
(Rewrite the sentence, using the reduced relative clause)
$\rightarrow $ Sometimes ...
5.The movie is fantastic. They are talking about it.
(Combine sentences, using preposition + Which or whom)
$\rightarrow $ The movie ...