1)The letter must be written by the secretary.
2)The books can’t be bought by this girl.
3)The car can’t be washed by him.
4)I must have my glasses mended.
5)The work cannot be done.
6)The snake might have been killed by her.
7) The house has to be cleaned.
8) Something should be done about global warming or else some types of penguins will perish from the earth.
9) A lot of cows can be raised on a productive farm.
10) The test must be finished now.