1. He studies ancient history in college.2. He studies the history of Russia at the moment.3. He taught history yesterday.4. Yesterday at 6 pm he taught history.5. He has been studying history for two years.6. He just learned the topic of history.7. Tomorrow he will learn five topics.8. When I called him, he already learned two topics9. When I called him, he taught the story for an hour and a half.10. Tomorrow by 6 o'clock I will learn all the topics.11. Tomorrow at 6 o'clock he will teach the history of Greece.12. By the time my father arrives, I will study history for several hours.