4. It isnt necessary to buy a first class ticket. ( have ) You............... a first class ticket. 5. Im sure he was at home last night. (must ) He.............at home last night. 6. You must never take your helmet off while you are riding a motorcycle.(all) Helmet must be worn.......................when riding motorbike. 7. I thought parking was allowed here. ( under impression ) I...................that the parking was allowed here. 8. His daughter continued to cry until he could not be seen any longer. (sight ) She continued to cry until he.......... 9. Im afraid that car is just too expensive. (means ) That car is..................

`4`. You don't have to buy a first class ticket.

- It + to be + (not) + necessary + (for O) + to V: (không) cần thiết (cho ai) để làm gì

= S + (aux V not) + have to + V: (không) cần phải làm gì

- Thì hiện tại đơn ( - ) S + do/does + not + V-inf + ...

`5`. He must have been at home last night.

- S + must have Vpp + ... : chắc hẳn làm gì

- Dịch: Anh ấy chắc hẳn đã ở nhà đêm qua.

`6`. Helmets must be worn at all times when riding motorbike.

- At all times: Mọi lúc

- Bị động của "must" S + must be + Vpp + (by O)

- Dịch: Mũ bảo hiểm phải được đội mọi lúc  khi bạn lái xe máy.

`7`. I was under the impression that parking was allowed here.

- S + to be + under impression + that + S + V: có ấn tượng làm gì

- Thì quá khứ đơn ( + ) S + was/ were + ...

`8`. She continued to cry until he was out of sight.

- out of sight: ngoài tầm mắt

- Dịch: Cô tiếp tục khóc cho đến khi anh khuất dạng.

`9`. That car is beyond my means.

- beyond one's means: vượt qua khả năng của ai

- Dịch: Chiếc xe đó vượt qua khả năng của tôi.