33. If COVID-19 hadn't broken out again, we could have gone to school.
(Câu điều kiện loại 3:

If + S1+ had+ PII, S2+ would+ have+ PII)

34. If Peter practiced English prequently, he could speak it fluently.

(Câu điều kiện loại 2:

If + S1+ V2/ Ved, S2+ would+ V)

35. A number of COVID-19 vaccines have just been imported by the Vietnam government.

(Bị động thì HTHT: has/ have + been + PII)

36. We should not throw away garbage improperly.

(should not V: không nên làm gì)

I. Rewrite the sentences as directed in bracket

33. Covid-19 broke out again, so we couldn’t go to school.

->If  Covid-19 hadn't broken again, we could have gone to school.

Câu đk loại 3: if+s+had+(not)+Vpp/c3, S+woul/could+have+Vpp/c3

34. Because Peter doesn’t practice English frequently, he can’t speak it fluently.

->If Peter practiced speaking English frequently, he could speak it fluently. 

Câu đk loại 2: If +S+Ved/c2                , S+would/could+V-inf

                                   was/were+adj

35. The Vietnam government has just imported a number of Covid-19 vaccines.

->A number of Covid-19 vaccines have just been imported by The Vietnam government.

S+have/has+Vpp+0

=S(đưa 0 về làm S)+have/has+been+Vpp/c3+(by+0)

II. Combine the sentence without changing the original meaning

36. Throw away garbage improperly is bad for the environment.

->We shouldn't throw away garbage improperly.

S+should/shouldn't+V-inf: nên/ không nên làm j