英语,将下列句子由直接引语改为间接引语,或由间接引语改为直接引语.
1.They were sure,“Mary isn‘t going to have the party.”
2.He said,"The earth is round."
3.Sue said,"I'm very excited about going on vacation."
4.The doctor asked,"Why didn't you take the medicine?"
5.Mike wanted to know if it snowed in winter there.
6.Lana said she would go to Marva's house on Friday night.