Грамматика, выберите правильный ответ

1. He was happy [A — to worked/B — working /C – to be working] at the famous locomotive-building plant

2. We expect this locomotive engine [A — showed /B — to show /C – has shown] good operation.

3. I want you [A — to help /B — help /C – helping] me with my research work.
4. It’s entirely possible to design a fuel filter element capable of retaining all particles large enough [A — caused /B — to cause /C – has caused] damage to the equipment.
5. He was seen [A — to came /B — came /C – to come] to labopatory early.
6. It is important for the meeting [A — to have been /B — to be /C – was] a success.
7. The experiment with new locomotive was said [A — to be /B — has been /C – were] very interesting.
8. This type of engine appears [A — have been /B — to be /C – had been] the most universal.

9. I couldn’t wait for them [A — to have finished /B — to be finish /C – to finish ] testing of new engine.
10. A new comfortable railway carriage was developed [A — to transport /B — to transported /C – have been transport] people over long distances.
11. The workers will use powerful machinery [A — assemble /B — to assemble /C – have to assemble ] these huge units.

12. They thought him [A — to have taken /B — to have take/ C – take] part in their experiment.

13. These two scientists happened [A — worked /B — to work /C – working] on the same problem.

14. The new locomotive engine proved [A — to be /B — is /C – has been] quite efficient.

15. The new locomotive fuel is assumed [A — was /B — to be /C – had been] both cheap and efficient