23. Choose one of the options to fill in the gaps.

1. My sister ___ to school when she met him.

a) was going b) will go c) went d) goes

2. I ___ the tickets by the beginning of the conference.

a) will have bought b) buy c) have bought d) will buy

3. Our pupils ___ a composition at this moment.

a) is writing b) will be writing c) were writing d) are writing

4. He ___ to Malta twice before he took me there.

a) had been b) has been c) have been d) was

5. She ___ for a year before he settled in London.

a) have been traveling b) had been traveling c) will be traveling

d) is travelling

6. She ___ a tasty dinner now.

a) cooked b) cooks c) is cooking d) was cooking

7. She is very tired now. She ___ round the city all the morning.

a) has been walking b) was walking c) will be walking d) walked

8. My friends ___ their homework now. They can not go for a walk.

a) were doing b) will be doing c) do d) are doing

9. I ___ work in India when I leave University.

a) am going to b) was c) did d) am

10. She ___ her trip round the world by the beginning of the next academic year.

a) had finished b) have finished c) will have finished d) has finished

11. The young scientist ___ his research work at the meeting at this moment.

a) introduces b) introduced c) is introducing d) will be introducing

12. They ___ these machine-tools for fifty years already.

a) are using b) use c) have been using d) used

13. When ___ the error in this programme?

a) have you discovered b) you discovered c) were you discover

d) did you discover

14. We ___ TV when she came.

a) are watching b) will be watching c) were watching d) watched

15. How long ___ this person?

a) did you know b) have you known c) are you known d) do you know

16. ___ they ___ this problem all day long tomorrow?

a) were, discussing b) are, discussing c) will, be discussing

d) will, discuss

17. The time of day and other circumstances ___ the body’s temperature.

a) affects b) is affecting c) has affected d) affect

18. By now, the worldwide installed capacity of renewable energy ___ that of nuclear power.

a) surpasses b) surpassed c) has surpassed d) had surpassed

19. Dinosaurs suddenly ___ extinct about 65 million years ago.

a) have become b) were become c) had become d) became

20. They ___ their examination from 5 till 7 yesterday.

a) passed b) will pass c) are passing d) were passing

21. Nitric acid ___ with most metals.

a) reacts b) react c) is reacts d) reacting

24. Choose one of the options to fill in the gaps.

1. At present Canada ___ a high-speed rail system.

a) have not b) does not have c) do not have d) is not having

2. By the 17th century, temperatures in the Northern Hemisphere ___ by half a degree Celsius compared with medieval times.

a) was falling b) fell c) has fallen d) had fallen

3. Recently, a scientist at the University of Illinois ___ a tiny device that can measure a wearer’s blood flow and wirelessly send that information to a computer.

a) has invented b) invent c) are inventing d) have invented

4. The students ___ in the library the whole last week.

a) will be sitting b) are sitting c) were sitting d) sat

5. Computers ___ such games as chess already.

a) have mastered b) are mastered c) has mastered d) master

6. The human brain ___ a built-in talent for working out depth from flat images.

a) have b) is having c) had d) has

7. He ___ his mobile phone for already 3 hours.

a) has charged b) has been charging c) is charging d) was charging

8. We hope the rain ___ very soon.

a) will be stop b) stops c) had be stopped d) will stop

9. By the time we woke, the snow ___.

a) had melted b) has melted c) melted d) will be melting

10. They ___ this question when the bell rang.

a) discussed b) will be discussing c) were discussing d) are discussing

11. He gave his reasons for what ___.

a) was happened b) had happened c) has happened d) happened

12. She ___ till you come.

a) was working b) is working c) will be working d) worked

13. If he ___ a favourable report on his work, he will work still harder.

a) receive b) will receive c) will be receive d) receives

14. I suspect that ___ an error in these calculations.

a) it is b) there is c) is d) be

15. We will watch you while you ___ this experiment.

a) will be making b) are making c) were making d) make

16. By the end of the week we ___ these samples for a month.

a) will test b) will have been testing c) will be testing

d) will have tested

17. A man was stopped by the policeman when he ___ to cross the street at the red light.

a) was go b) was going c) had been going d) is going

18. He ___ from a business trip by the end of next week.

a) will arrives b) has arrived c) will arrive

d) will have arrived

19. Scientists ___ the existence of neutron stars as long ago as 1934.

a) have predicted b) predicted c) has predicted d) had predicted

20. I ___ an article on internal combustion engines when the teacher came.

a) will be reading b) am reading c) read d) was reading