Put the verb in brackets in the Past Simple , Past Perfect or Present perfect.
18. The boy ...... (say) that he .......... (do) all his homework before he ............. (go) to bed.
19. The children ............. (begin) to do the exercise after they .................. (review) all the rules.
20. He .............. (make) a report on the history of England after he ........... (read) a lot of books about it.