`31` They haven't left their homeland for over two years.

`=>`  It + to be + time + since + S + Ved/ V2 ... `=` S + have/has + not + Vpp + ... + for + time

`32`I asked Mai how many cars there were in front of her house.

`=>` Câu tường thuật: S + asked/ wanted to know/ wondered/... + (O) + WH-words + S + V (lùi thì)

`=>` Quá khứ đơn ( + ) S + was/ were + ...

`33`I wasn't introduced to newcomers in the festival.

`=>`  S + was/ were + not + Vpp + (by O)

`=>`  "No one : không ai" mang nghĩa phủ định

`34`The food was so bad that the children couldn't eat it.

`=>`S + to be + so + adj + that + S + V: quá ... đễn nỗi ...

`=>` Thì quá khứ đơn` ( + ) `S + was/ were + ...

`35`There is no point in persuading her to join in that activity.

`=>`  There + to be + no point + in + V-ing: Chẳng có lí nào để làm gì

`=>` Thì hiện tại đơn ( + ) S + am/is/are + ...

Đáp án: + Giải thích các bước giải:

`31)`

`to` They haven't left their homeland for over two years,

`-` HTHT: S + have/has + not + Ved/ Cột `2` + for + time 

`32)`

`to` I asked Mai how many cars there were in fron of her house

`-` HTĐ `to` QKĐ

`-` Câu gián tiếp: S + asked/wanted to know/wondered + O + Wh + S + V(lùi thì)

` ( + )` S + was/were + O

`-` Your `to` her

`33)` 

`to` I wasn't introduced to newcomers in the festival

`-` Bị động QKĐ:

`( - )` S + was/were not + Ved/ Cột `2` + ( by + O)

`-` Chủ ngữ là I `to` wasn't

`34)`

`to` The food was so bad that the children couldn't eat it.

`-` S + tobe + so + adj + that + S + V: quá... đến nỗi

`-` can `to` could 

`-` Couldn't + V: không thể làm gì

`35)`

`to` There is no point in persuading her to join in that activity.

`-` There is/are + no point in + V-ing: chẳng có lí nào... để làm gì

`to` HTĐ: 

`( + )` S + am/is/are + O

`#Ph`