преобразовать выражение в многочлен стандартного вида 3(x-y)^2

1 Underline the correct tense.

1 At noon yesterday, the staft were having/are having their monthly meeting.

2 My father works/used to work as a laxi driver five years ago.

3 Did you arrive/Were you arriving at the airport on time?

4 Two hundred years ago, people travelled/had travelled abroad by ship.

5 The teacher was giving/gave the students a test when the principal came/was coming into the classroom.

6 Did your grandfather use to went/go birdwatching when he was a young man?

7 Nico e is ciosing/closed the windows, sets/set the alarm and left/was leaving the house.

8 I walked was walking on the beach in Bali this time last woek/

9 Did Arnold attend/Was Arnold attending the conference yesterday?

10 Amy was sitting/sat on the park bench while the children play/were playing.

11 Billy had/was having a fantastic time at the party on Saturday night.

12 Conrad didn't use to socialise/socialised much two years ago.