Исправьте ошибки: 1. it is hot, but it has been cold two days ago. 2. the first world war has begun in 1914. 3. hurry up! the lesson just began! 4. does he wear a raincoat now? 5. do you go to the museum tomorrow? 6. i have opened the door and looked out. there was no one there. 7. he's met you, isn't he? 8. he's having breakfast, hasn't he? 9. what he cooked?

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. There was no one there.
7. He's met you, HASN`T he?
8. He's having breakfast, ISN`T he? 
9. what DID he cook?