1. Before testing, the observations should be made.
2. Many years ago people learned protecting their houses from lightning strike.
3. There are different ways of obtaining electric current.
4. The scientists continued studying of new phenomena.
5. The pyrometer is used for measuring hot metal temperature.
6. Franklin invented the lighting rod for protecting the buildings from lightning strikes.
7. Walking is very good.
8. The nuclear power reactor is used for energy obtainig.
9. The using of new materials contributes to further technology development.
10. While explaining the physical phenomena the teacher made several experiments.
11. The increasing of ebergy production is necessary.
12. The inventor was against the changing of this device construction.
13. Having seen this device in operation, the students decided that it was reliable.
14. We finished discussing this problem by the end of the week.