Change these sentences into passive form (simple past)

Change these sentences into passive form (simple past) :
1. People invented color TV in 1950.
2. My father took me to HCM City last week.
3. They bought many souvenirs in Nha Trang.
4. She read the letter many times last night.
5. Hoa met Tim at the market yesterday.
6. She didn't introduce me to her mother.
7. Thu helped him do this homework.
8. They didn't invite me to the birthday party.
9. My father planted this tree.
10. They built that house in 1972.