6. Where did they invent gun-powder?
Where gun-powder was invented ?
7. How do you make this delicious meal?
How this delicious meal is made?
8. Why does he water these plants so rarel y?
Why these plants are watered so rarel ?
9. Producers sell about 1.2 billion gallons of Sprite every day.
About 1.2 billion gallons of Sprite are sold by Producers ?
10. The police didn't find the missing girl last weekend.
The missing girl .wasn't found by The police last weekend?
11. A passer-by caught the shoplifter and took him to the local police station.
The shoplifter.was caught and taken to the local police station by A passer-by
12. The hotel management requests the guests to leave the rooms by midday.
The guests are requested to leave the rooms by The hotel management by midday 
13. Where did they hide all the sports equipment?
Where all the sports equipment are hidden ?
14. Tourists don't visit this museum very often.
This museum isn't visited very often by Tourists
15. How often does he re-install his computer?
How often his computer is re-installed ?
16. In the first stage of the process they roast and grind coffee beans.
Coffee beans are roasted and ground In the first stage of the process
17. The Polish archaeologists were the first to excavate and describe this temple.
This temple was the first to excavated and described by The Polish archaeologists
18. The professor reminded the students about the due-date for handing essays.
The students were reminded about the due-date for handing essays by The professor
19. People speak English all over the world.
English is spoken all over the world
20. They do not permit smoking in the auditorium.
Smoking isn't permited in the auditorium
21. Did they deliver your goods safely?
were your goods delivered safety  ?
22. People didn't forget his brave deeds.
His brave deeds weren't forgotten 
23. I could see nobody slept in this bed last night.
This bed could be slept by nobody I could see last night
24. Did you hear that robbers broke into their house last weekend?
Did you hear that their house was broken into by robbers last weekend  ?