Перепиши предложения в пассивном залоге. Обрати внимание на употребление модальных глаголов в пассивных конструкциях.

1. Someone must warn them about the danger.
They _____ about the danger.

2. People must protect wildlife.
Wildlife _________

3. Mary must bring the letters today.
The letters ______by Mary today.

4. We have to fix the roof as soon as possible.
The roof _______ as soon as possible.