12. You are not allowed to leave the room without permission. (mustnt)

____________________________________________

13. Its good idea to swallow rapidly if you have hiccups. (should)

____________________________________________

14. They once started these machines by hand.

They used to _________________________________

15. He doesnt get up late anymore.

He _________________________________________

16. David had gone home before we arrived.

After ______________________________________

17. We had lunch then we took a look around the shops.

__________________________________________

giải chi tiết giúp e nhé

`12.` You musn't leave the room without permission

`->` S + be + not + allowed + to V

`=` S + musn't + V0 + O

`13.` You should swallow rapidly if you have hiccups

`->` It is good idea + (for sb) + to V

`=` S + should + V0 + O

`14.` They used to start these machine by hand

`->` Cấu trúc diễn tả một thói quen trong quá khứ, nhưng giờ đã không con

`=>` S + used to + V0

`15.` He used to get up late

`->` Cấu trúc diễn tả một thói quen trong quá khứ, nhưng giờ đã không con

`=>` S + used to + V0

`16.` After David had gone home, we arrived 

`->` Before + S + V2, S + had VpII

`=` After + S + had VpII, S + V2

`17.` After having lunch, we took a look arround the shops

`->` Rút gọn mệnh đề after

`=>` After + having + VpII, S + V2 + O

$12$. You mustn't leave the room without permission.

$-$ S $+$ must (NOT) $+$ V inf

`***` without sth (a): thiếu thứ gì đó

`***` permission (n): sự cho phép

$13$. You should swallow rapidly if you have hiccups.

`@` Điều kiện loại 1:

$-$ If $+$ S $+$ V inf, S $+$ will/should/must/may/etc $+$ V inf

`***` rapidly (a): liên tục

`***` hiccup (v,n): nấc

$14$. They used to start these machines by hand.

$-$ S $+$ used to $+$ V inf

`***` do sth by hand (v): làm gì đó bằng tay

$15$. He used to get up late.

$-$ S $+$ used to $+$ V inf

$-$ ''used to'' chỉ hành động diễn ra trong QK và h ko còn diễn ra nữa

$16$. After David had gone home, we arrived.

$-$ S $+$ had $+$ Ved/PTII $+$ O

$17$. After having lunch, we took around the shops.

$-$ After $+$ S $+$ V-ing, S $+$ V inf $+$ O

$-$ S $+$ Ved/ cột 2

`***` take around sw (v): đi xung quanh nơi nào đó

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