По what were the pupils doing during the lunchtime

если только один раз, то: six, mix, his, sigh, pig, gig, big, limp. если все буквы можно употреблять несколько раз, то: high, philips, philip, shit, hiss, hill, bill, bilimbi (огуречное дерево).

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)