Укажите предложения, в которых «one/ones» является заменителем существительного (таких предложений должно быть 5).
1. One can see that electrons in crystals have wave properties.
2. The problem to be solved is in fact a theoretical one.
3. To heat a body one should place it in contact with another body at a higher temperature.
4. One must test the device several times.
5. The second device was tested about a month after the first one.
6. One can increase effectiveness applying this method.
7. It is necessary to use a new method, not the old one.
8. One uses special devices to measure speed, weight and length.
9. His last book is good, but the previous one is better.
10. Among the numerous disadvantages of this device power loss is the most evident one.