Jawaban:

1. Ann said to her friends, "My father has stopped smoking since five years ago." >> Ann told her friends that her father has stopped smoking since five years ago.

2. The people said, "Smoking which is the cause of lung cancer is a bad habit which I can not give up." >> The people said smoking is the cause of lung cancer, and is a bad habit which they cannot give up.

3. Chintya asked John, "Will you watch the film with me next week?" >> Chintya asked John if he want to watch a film with her next week.

4. Rafi asked Sarah, "What were you doing when I came to your house yesterday?" >> Rafi asked Sarah what were she doing when he came to her house.

5. My parents said to my sister, "Don't go to Surabaya by yourself. You must accompanied by your brother." >> My parent told my sister that she is not allowed to go to Surabaya by herself, she must accompanied by her brother.

6. Dinda asked Bella, "Why does your father go to America so often?" >> Dinda asked Bella why does her father go to america so often?

7. "How much time will you spend your time to finish your exercise" The teacher asked the students. >> The teacher asked the studnets how much time they'll spend their time to finish their exercise.

8. The children said, "We had done our task before we watched the football game on TV." >> The children said that they had done their task before they watched the football game on TV.

9. "How long have you been working in this company before you move to Japan?" I asked Anisa. >> I asked anisa how long have she been working in this company before she moved to Japan.

10. Mother asked Belinda, "Do you remember the city where your father was born". >> Mother asked belinda if she remember the city where her father was born.

Penjelasan:
The following are the rules for converting direct speech to indirect speech:

1) Remove all quotation marks and inverted commas.
2) Always put a full stop at the end of a sentence.
3) The verbs' tenses should be modified inside quotation marks and commas.