1. These books (ответ) very quickly. (to sell out)
2. How many cars (ответ)? (to damage)
3. How much water (ответ)? (to pollute)
4. The door (ответ) by a man. (to open)

вот правельный ответ.

kate's cake is tastier than ann's cake,isn't it.

cake-единственное число поэтому is.

все ваши предложения в прошедшем времени,поэтому используем past perfect passive.

they said the medicine had been prescribed by the doctor.

  he understood that the house had been robbed by the thieves.

  she said he had been seen the night before with a pretty girl in the club.

  he said that his walkman had been given to him by his mother as