1. What WERE you DOING when I CAME in? 2. When I CAME to his house, they TOLD me that he HAD LEFT an hour before. 3. On checking up his answers he FOUND out that he HAD MADE several mistakes. 4. When I LEFT (WAS LEAVING) home, the snow HAD already STOPPED, but a strong wind WAS BLOWING. 5. HAVE you READ this book? — Yes, I HAVE READ it . I THINK it IS very interesting. 6. What ARE the children DOING now? — Oh, they ARE PLAYING the new table game which I BOUGHT for them the day before yesterday. 7. They HAVE REACHED the corner of the street by now and ARE STANDING at the bus stop. 8. After we HAD WALKED (HAD BEEN WALKING) about two hours, we arrived at a picturesque glade covered with fresh grass. 9. We could not go out because it HAD BEEN RAINING hard since early morning . 10. She HAS BEEN TEACHING at our school for twenty years now.