Past Simple vs Present Perfect. 1. l'm hungry. I didn't​

1. Two men were arrested when they tried to sell a painting that (had been stolen) from Mrs. Hilton’s collection. It (was given) to her as a wedding present.
2. Jane was surprised to find the fridge empty. All the food (had been eaten).
3. The Kiddles were able to go to the concert as the tickets (had been booked) long before.
4. The newspaper report said that lately there (had been) a serious decline in the number of people qualifying as teachers.
5. By the end of the next month over 20 old buildings (will have been demolished).
6. The newspaper report read that a ban on tiger hunting (had been imposed) to prevent the instinction of tigers.
7. When the boss entered the room in the morning he saw that all the accounts (had been done).
8. The new software trial (had been completed) and the staff were ready to release it.
9. Columbus discovered America though at first he thought he (had reached) Asia. Before he discovered it people (had believed) that the earth was flat.
10. Scott reached the South Pole in 1912 but Amundsen (had beaten) him by a month.

If you drive along the river bank it is twenty miles out of your way.
If you take your mobile phone into class, it must be turned off.
We do not use calculators when we write tests.
If you push this button, the volume increases.
If you close the door, it locks automatically.
I wear my old boots when I work.
When I cook salads, I use only olive oil.
When I concentrate, please do not to make so much noise.
Unless prices rise, it is not a good investment.
Unless someone asks you politely, refuse to do anything.