Очень странное задание, потому что здесь используется не только Past Simple, но и Present Perfect. В любом случае я дала ответ согласно условию.
3) Did you enjoy
4) did
5) loved
6) thought
7) were
8) did you stay
9) were
10) had
11) had (did) - не уверена
12) saw
13) Did you learn
14) did
15) did
16) studied
17) went
18) found
19) was
20) Did you talk
21) knew
22) wanted
Надеюсь, помогла