Составить к этому предложение отрицательное предложение : they walked to school yesterday.

b: then where have you been? (present perfect)

a: oh, nowhere. i wanted (past simple) to go to america two years ago,but now i don't want to go there.

b: why?

a: i understood (past simple) that my wish is impossible, so i abandoned(past simple) that idea. 

и 2-я

b: have you heard some interesting news? (present perfect)

a: no.

b: i heard (past simple) that brian flunked (past simple) his exam last week. 

a: why did (past simple)he flunk the exam?

b: he lost (past simple)his homework, so he didn't repeat a topic.(past simple)

1. my sister is leaving to her place at the moment

2.i read this book yesterday

3. you are playing the piano tomorrow

4.we are returning from   the museum now.

5. our friends didn't see mary every day

6. the new school began to work last year

7. he often speaks to me

8. he was discussing the problem the whole morning yesterday

9.i will not be reading this article at 2 o'clock tomorrow.