change the voice in passive

1.I help

2.I am selling

Could I please have reliable answers as quick as possible(My final exam is on Thursday)?

1. He made a remarkable discovery.(Change into passive voice)
2. The postman leaves the letters at the society gate. ( Change into passive voice)

who has done this ? change to passive voice...can u help

hi , 

i need help in changing these sentences into passive 

1. People eat thirty-five million hamburgers every day.
2. The Industrial Revolution helped develop new technologies.
3. Most young people like chewing gum.
4. Where did they invent gunpowder?
5. How do you make this delicious meal?
6. Why does he water these plants so rarely?
7. The professor reminded the students about the due-date for handing in essays.
8. Did you hear that robbers broke into their house last weekend?
9. Who wrote it?
10. What did he write it with?
11. How can I get from the station to the airport?
12. Can you get coffee on the train?
13. Do you play rugby?
14. Can parents visit the school at any time?
15. Can I bring my dog into the compartment with me
16. Does he get people to make all his shoes in Italy.
17. Do you ask someone to type your essays?
18. Was her leg broken in the car crash?
19. When are you going to pay someone to develop those photos?
20. Will you divide the loan into convenient instalments?
21. Have they delivered my new music system yet?
22. How long has this butcher been delivering meat for you?
23. Why haven't you sent the invitation to Mark Taylor, yet?
24. A few groups of tourists have already visited this modern wonder of the world.
25. Someone will probably mug you if you walk in that part of the town alone.