1 What WERE you doing when the police arrived?
2 Mary can't answer the questions. She HASN'T read the text yet.
3 It is often snowS in December.
4 The lesson started twenty minutes AGO.
5 These pupils FINISHED Unit Fifteen last week.
6 They have been WRITING the test for an hour.
7 John HAS BEEN doing exercises since 8 o'clock.