1. Dangerous radiation was released into the environment by a nuclear reactor.

S + was/were + V3/ed (bị động - QKĐ)

2. The pollution problem has been discussed by the students since last week.

S + has/have + been+ V3/ed (bị động - HTHT)

3. An effective solution has to be found out to ease the pollution in this river.

S + has/have +to be + V3/ed 

4. This house and these cars are going to be painted by the Greens for Christmas Day.

S + am/is/are + going to be + V3/ed (bị động - thì TLG)

5. 

- It is thought that Maradona is the best football player in the 20th century.

- Maradona is thought to be the best football player in the 20th century.

S1 + V1 + that + S2 + V2 

→ S2 + be + V3/ed (V1) + to + V1 (cùng thì)

→ S2 + be + V3/ed (V1) + to have + V3/ed (khác thì)

→ It is + V3/ed (V1) + that + S2 +V2

6. The last time students went to school was 4 months ago because of covid-19.

The last time + S + V2/ed + was + time 

`color{orange}{~LeAiFuRuiHuiBao~}`