Определите функции слова for.
1. The young animals are practically porkilothermic at birth and continue to be so for some days. 2. They could not translate the article for it was written in French. 3. Each organism establishes for itself a level of nitrogen metabolism which is modified only with difficulty. 4. Carbohydrates and fats are food substances which do not contain nitrogen; they have high fuel value, and so are able to serve for the production heat.
1 в течение
2 причина
3 возвратность
4 служить причиной