Заполните пропуски глаголом to see в соответствующем времени. I ... a friend in the library yesterday. I ... him there

 I saw a friend in the library yesterday. I had seen him there many times before, but he was so busy that I did not speak to him. When I spoke to him he said that he had never seen me at the library. He concentrates on his work. He sees only his book. The teacher has seen him there many times, but he doesn’t see even her. He sees many important facts in books, however, and tells the class about them. He sees and reads more important documents than all the rest of our class put together.