1) I don't know that boy. I have(had) never met him.(будет и так и так правильно)
2) How long it taking to clean your room ?
3) It is rain hardly. Let's stay at home.
4) There will a museum in this sguara next year.
5) Have you invited many people to the New Year party?
6) Who washed the floor ?
7) I am sure the film interesting.
8) Has he locks the door? - Yes, he has.
9) Are be there any books for the boys?
10) They bought this book three months ago.