Tammy must open the door.
The door must be opened by Tammy.
Rich people can spend a lot of money.
A lot of money can be spent by rich people.
You must not touch this button!
This button must not be touched.
We must put this problem to an end as soon as possible.
This problem must be put to an end as soon as possible.
Little kids can't read books.
Books can't be read by little kids.
Max has to learn Geography.
Geography has to be learned by Max.
Students must answer a lot of questions.
A lot of questions must be answered. (by the students)