Переведите следующие предложения на русский язык, обращая внимание на сказуемое в Passive Voice.
1. The metric system was worked out by the French Academy of Sciences in 1791. 2. Interesting and important research is being done at our University. 3. In Russia the metric system was adopted in 1918.
4. The better results have not been obtained yet. 5. A great number of experiments had been made before the problem was solved. 6. During the last hundred years many methods of building have been discovered. 7. The Metro is extended to provide a quick service to the capital’s centre.