16.
I was waiting until everybody will have left the meeting place.

17.
In quick time he got attached to a renowned leader and politician.

18.
An educated man's way of life can be contrasted to that of an illiterate person.

19.
In the past, services of backward communities and weaker sections of society were used without payment of some kind.

20.
The contractor did not keep his promise that the work will be finished before the end of the week.