`11.` Have the Christmas cards been sent to your family (by you)?

`12.` Alice was appointed secretary for the meeting by the committee.

`13.` The broken cup is hidden in the drawer (by him).

`-` hide - hid - hidden: giấu, trốn, trộm cắp

`14.` This room is kept tidy all the time (by them).

`-` keep - kept - kept: giữ

`15.` The party was voted a great success.

`16.` Ann was given some bananas and some flowers. (by us)

`-` give - gave - given: cho

`17.` The fridge was moved into the living room (by them).

`18.` Some cups of tea were bought to the visitors in the next room (by her)

`-` buy - bought - bought: mua

`20.` The note wasn't taken to the manager (by the secretary).

`-` take - took - taken: đưa

_______________________

`-` Thì hiện tại đơn:

A`:` S + V(s/es)

`->` P`:` S + am/ is/ are + V(pp) + (by O).

`-` Thì quá khứ đơn

A`:`

$(+)$ S + Ved/ V2

$(-)$ S + didn't + Vinf

`->` P`:` 

$(+)$ S + was/ were + V(pp) + (by O).

$(-)$ S + was/ were + not + V(pp) + (by O).

`-` Thì hiện tại hoàn thành:

A`:`

$(+)$ S + have/ has + V(pp)

$(?)$ Have/ Has + S + V(pp)?

`->` P`:`

$(+)$ S + have/ has + been + V(pp) + (by O).

$(?)$ Have/ Has + S + been + V(pp) + (by O).