16. All flights have been cancelled because of the bad weather
17. This task should be done by Peter
18. The victims have been provided with food and clothing
19. A lot of money is spent on advertising every day
20. English is spoken in almost every corner of the world
QKĐ: S + was/ were + PP + (by O)
HTĐ: S + am/ is/ are + PP + (by O)
HTTD: S + am/ is/ are + being + PP + (by O)
HTHT: S + have/ has + been + PP+ (by O)
TLĐ: S + will be + PP + (by O)
TLG: S + is/ am/ are + going to + be + PP + (by O)
S + modal verb + be + PP + (by O)
