Complete the sentences with the correct passive form of the verbs in brackets.

1. Dolphins………………………………. (say) to have their own patterns of communication.

2. That’s an amazing photograph! Do you know who it……………………………(take) by?

3. The cat ran up the tree because it…………………………………. (chase) by a dog!

4. This map of Roman roads …………………………..(draw) by an ancient historian.

5. All the nuts that were lying on the ground……………………………(collect) by the squirrels.