пожалуйста помогите расскрыть скобки в правельном времени.Заранее спасибо

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.
11. Ring me up as soon as you COME home.
12. He BEGAN to write his composition at three o'clock. It is already eleven, and he HAS BEEN still WRITING (IS STILL WRITING) it.He says he WILL HAVE FINISHED it by twelve.
13. We HAVE BEEN HELPING our librarian to put the books in the right order for already three days, but we HAVE ARRANGED only half the books.

what were you doing when I came in?
When Icame to his house, they told me that he had left an hour ago.
...he found out that he had made several...
...left home, the snow has already stopped,...wind was blowing
всё, дальше лень, открой грамматику, и разберись с этим,

after we(to walk) about two hours, we arrived at a picturesque glade covered with fresh grass