В слове Demosthĕnes ударение падает: Demosthenes;

Demosthenes;

Demosthenes;

Demosthenes.

  1the teacher said to jack thet he is working hard and he is a good boy.2the old man said to the girl thet shi can sing perfectly and he think shi will be a famous singer.5the student said thet he can*t answer this question and don*t understand it.

1. i exercise regularly in summer but more to do in winter. 2. she usually walks slowly but now she is walking even   faster . 3. nina speaks loudly but mary speaks even   louder . 4. he runs fast, than other boys. 5. i don’t sleep enough, less   than 8 hours. 6. he behaves badly, than other boys. 7. i smile often, more than my sister. 8. peter lives far from school, but ann lives closer .

я думаю, что  4 и в 6 предложениях ничего изменять не надо. может я ошибаюсь.