Написать предложения в отрицательной форме: 1. I must write a letter. 2. You must put on your winter coat. 3. We must get up at seven o’clock. 4. I must do my lessons every day.

сокращать так mustn't это неформально тоесть нельзя так написать на экзамене, must not-это форьмальный вид сокращении. Если это задание теста или экзамена, используйте формальный вид

1. I mustn't write a letter

2. You mustn't put on your winter coat.

3. We mustn't get up at 7 o'clock.

4. I mustn't do my lessons every day.

End of August, they made a lot of money.
End of the year they defeated the enemy fleet.
He reminded me of this event after John left.
We burned dry leaves before the snow fell.
Rainbow appeared in the sky after the rain stopped.
She cut flowers for how we came to the greenhouse.
Dodo - an extinct species of birds. They disappeared after people began to hunt them.
The fire destroyed the building before firefighters arrived.
Miss Marple to solve complex criminal problem before it could make the police.
Robert spoiled little new toy you now Pope explained to him how to play with her.

By the end of August they made a lot of money.

By the end of the year they developed the enemy fleet.

He reminded me about this event after John left.

We burned dry leaves before the snow fell.

Rainbow appeared in the sky after the rain stopped.

She cut flowers before we came into the greenhouse.

Dodo - extinct species of birds. She disappeared after people started on her hunt.

A fire destroyed the building, before the arrival of fire.

Miss Marple allowed complicated criminal problem before it could make the police.

Little Robert spoiled new toy before dad explained to him how to play with her.