1 It is hot, but it WAS cold two days ago.
2 The First World War BEGAN in 1914.
3 Hurry up! The lesson HAS just BEGUN.
4 IS he WEARING a raincoat now?
5 WILL you go to the museum tomorrow?
6 I OPENED the door and looked out.
7 He HAS met you, HASN'T he?
8 He is having breakfast, ISN'T he?
9 What DID he COOK?