Đáp án+Giải thích:
6. They haven’t finished their homework yet.
=> Their homework hasn't been finished yet.
7. Nobody could solve this mathematical problem.
=> This mathematical problem couldn't be solved.
8. Throwing rubbish pollutes the environment.
=> The environment is polluted by throwing rubbish
9. Elias Howe invented the sewing machine in 1895.
=>The sewing machine was invented by Elias Howe in 1895
10. People spend a lot of money on advertising every year
=> A lot of money is spent on advertising every day.
Giải thích:
+Passive voice:
-Past simple: S + was/ were + PP + (by O)
-Present Simple: S + am/ is/ are + PP + (by O)
-Present Continuous: S + am/ is/ are + being + PP + (by O)
-Present Perfect: S + have/ has + been + PP+ (by O)
-Future Simple: S + will be + PP + (by O)
-Near Future: S + is/ am/ are + going to + be + PP + (by O)
+Special: S + modal verb (should, must, have to, can,...) + be + PP + (by O)