1. They were happy to take part in our expedition.
2. She wanted to be answered at once.
3. He was happy to be working with the famous scientist.
4. It’s very difficult to drive a car in a big city.
5. Water may be used to drive dynamos which generate electricity.
6. Sputniks do not need any additional energy to move along their orbit.
7. Newton made use of the three laws of motion to explain the movement of the Moon around the Earth and of the planets around the Sun.
8. To extend the main street they had to destroy some old buildings.
9. The workers will use powerful machinery to assemble these huge units.
10. In this area there are no monuments to speak of.
11. Dalton’s atomic theory was the first to make successful use of the old Greek theory of atoms in chemistry.
12. The new channel to be constructed here will be the longest in the country.
13. The new branches of industry to be developed in this part of the country are metallurgy and radio engineering.
14. Another reason to consider is the absence of necessary facilities for the experiment.