$\text{1.}$ I was given a nice gift when I was fourteen.
$\text{→}$ Câu bị động thì QKD: $\text{S + was/ were + Ved/ P2 + (by)}$
$\text{2.}$ This letter must be typed before the director leaves here for London.
$\text{→}$ Câu bị động với modal V: $\text{S + modal V + be + Ved/ P2 + (by)}$
$\text{3.}$ Why don't you work? It is 8.30 now.
$\text{→}$ Tại sao bạn ko làm việc? Bây giờ là 8.30 rồi đấy.
$\text{4.}$ Look! Those dogs and cats are being fed by a little girl.
$\text{→}$ Look chia HTTD
$\text{→}$ câu bị động thì HTTD: $\text{S + be + being + Ved/ P2 + (by).}$
$\text{5.}$ She said she would pick me up at the airport the following morning.
$\text{→}$ the following morning ← next morning ⇒ chia TLD ⇒ dùng will
$\text{→}$ would ← will