1.I'm sure you are very tired after working so hard.(must) 2.If he is not in the office,then I'm sure he's working at home.(must) 3.It is necessary for them to practice hard to win the match(must) 4.Visitors are not allowed to take photos in the museum(mustn't) 5.It is wrong of you to throw rubbish on the floor(mustn't)

1.I'm sure you are very tired after working so hard.

`⇒` You must be very tired after working so hard.

Cấu trúc : Must be + adj

2.If he is not in the office,then I'm sure he's working at home.

`⇒` He must be working at home if he is not in the office.

Cấu trúc : Must be + V – ing

3.It is necessary for them to practice hard to win the match

`⇒` They must practice hard to win the match.

Cấu trúc : S + must + V…

4.Visitors are not allowed to take photos in the museum

`⇒` Visitors mustn't take photos in the museum.

Cấu trúc : S + mustn’t (must not) + V…

5.It is wrong of you to throw rubbish on the floor

`⇒` You mustn't throw rubbish on the floor.

Cấu trúc : S + mustn’t (must not) + V…