Добрый день! , , правильно определить функцию инфинитива. 1. we knew him to be a good doctor. 2. the article to be published was written by his brother. 3. to master english we must work regularly. 4. to master english is our duty. 5. this question is too complicated to be answered at once. 6. the conference discussed some new methods to be used in teaching english.