6. Roger didn't give any explanation why he was late for school.
7. I felt very tired when I came home so I went straight to bed.
8. Mr Pitt took his case and left.
9. What were you doing at 10 o'clock yesterday morning?
10. I wanted to borrow that new book but she had already lent it to someone else.
(P.S. Жалко, что не были указаны времена, которые нужно использовать, но я думаю, что сделал все правильно)