2) Big is talking to Bug on the phone. Put the verbs in the correct form and you will learn what they say.
Big: Hi, Bug. I have just come home.
Bug: Hi, Big. Have you (seen) Johnny?
Big: No, he has not (come) back yet. He has (gone) back in time.
Bug: What? We, computer viruses, have never been back in time, and this silly boy has (gone) there?
Big: Right. We have never (spoken) to people from the old times. We have never (worn) old costumes.
Big: But in the old times there were no computers, so it is not interesting.