Quy tắc chuyển từ câu chủ động sang câu bị động                                        giúp em với ạ

1Who invited her to the party? 

          -  The party be invited  by who ? 

           - The party  was invited by whom ? 

           - By whom the party was invited ? 

          -  By whom was the party  invited? 

2 When did they buy this car? 

3 Was Mary helping her mother in the kitchen? 

4 Will you invite her to your birthday party? 

 5  He cleans the house 

6 He is cleaning the house 

 7 He has cleaned the house 

  8  He cleaned the house 

 9 He was cleaning the house 

 10 He had cleaned the house 

11 He should clean the house 

12  He will clean the house 

In 2005, Chad Hurley and Steve Chen, two software designers from Silicon Valley in California, were invited to a dinner party. Several people had brought their camcorders to the party and these people were complaining about (1) ................................ difficult it was to share home videos online. That was when Chad and Steve came up (2) ................................ the idea for YouTube, the site which makes (3) ................................ easy to upload home videos onto the Internet. They formed a company, borrowed some money (4) ................................ set themselves up in business.

It turned (5) ................................ that millions of people already had short home video clips that they thought it (6) ................................be fun to share with other enthusiasts around the world.

Launched in December 2005, YouTube soon contained more (7) ................................ a million short video clips. People were uploading 8000 clips a day, and watching three million a day. They had mostly heard about the site through word (8) ................................ mouth, email and hyperlink, and eighty percent of the clips had (9) ................................made by amateurs.

So why was YouTube such an immediate success? Researchers found that, (10) ................................average, people were spending fifteen minutes on the site during each visit, which was (11)................................. time to view several short funny clips. In (12) ..............................words, they were using YouTube to give them a little break from their work or study.