Вставьте в предложения подходящие по смыслу слова из предложенных групп однокоренных слов: differ, different, difference; to vary, various, variety; efficient, efficiently, efficiency.
1. The enterprise is working ... .
2. There is a ... of reasons for high unemployment in this region.
3. Prices of the same agricultural products ... from region to region.
4. There is not any ... between these two methods, only the names ... .
5. These two economists are interested in ... fields of economics.
6. They have raised ... of their work by means of new machinery.