1. Alex and Andy have cleaned the cage.
2. Emily has watered the plants.
3. Daniel and Chris have fed the animals.
4. Alice has sweep the paths.
5. John has walked the dog.
6. Tom and his friend have repainted the zoo door.
7. Ann and her sister have decorated the school zoo.
Present Perfect образуется таким образом:
I/we/they/you + have + глагол в 3-ей форме/окончание ed (зависит от того, правильный или неправильный глагол);
He/she/it + has + глагол в 3-ей форме/окончание ed (зависит от того, правильный или неправильный глагол).