I need some exercises for converting Simple sentences into Complex and compound sentences

1. Do you know the cost of this bicycle?    
Ans:Can you tell me how much does this bicycle costs?

2 . I request your help.
Ans: I request you to help me.

3. I have no where to sit.
Ans: I do not have any place where I can sit and eat. 

You can also take assignments on the  meritnation website.
Regards